NCAR S-band Polarimetric Radar (S-POL)
Scientists' Log Book Transcription
10 January 1999 – 28 February 1999
All times are in UTC unless noted otherwise.
S-POL LOGBOOK #1: 1/10/99 - 2/10/99 *
January 10, 1999 *
January 11, 1999 *
January 12, 1999 *
January 13, 1999 *
January 14, 1999 *
January 15, 1999 *
January 16, 1999 *
January 17, 1999 *
January 18, 1999 *
January 19, 1999 *
January 20, 1999 *
January 21, 1999 *
January 22, 1999 *
January 23, 1999 *
January 24, 1999 *
January 25, 1999 *
January 26, 1999 *
January 27, 1999 *
January 28, 1999 *
January 29, 1999 *
January 30, 1999 *
January 31, 1999 *
February, 1 1999 *
February 2, 1999 *
February 3, 1999 *
February 4, 1999 *
February 5, 1999 *
February 6, 1999 *
February 7, 1999 *
February 8, 1999 *
February 9, 1999 *
February 10, 1999 *
S-POL LOGBOOK #2: 2/10/99 - 2/28/99 *
February 10, 1999 (continued): *
February 11, 1999 *
February 12, 1999 *
February 13, 1999 *
February 14, 1999 *
February 15, 1999 *
February 16, 1999 *
February 17, 1999 *
February 18, 1999 *
February 19, 1999 *
February 20, 1999 *
February 21, 1999 *
February 22, 1999 *
February 23, 1999 *
February 24, 1999 *
February 25, 1999 *
February 26, 1999 *
February 27, 1999 *
February 28, 1999 *
S-POL LOGBOOK #1: 1/10/99 - 2/10/99
January 10, 1999
LOCAL TIME = UTC TIME – 4 HOURS
S-pol location: 11.22126 S, 61.99820 W; 201 m altitude
TOGA location: 10.7739 S, 62.3373 W
Dual-Doppler baseline: D x = 37.008 km, D y = 49.736 km; R = 62.0 km
UND call-sign: 77ND
January 11, 1999
Learning ZEBRA and S-pol scan controller.
January 12, 1999
Building scans on S-pol.
1551-1555 Vertically pointing scan. Zh=15-20 dBZ; Vr = -2 m s-1.
January 13, 1999
Building and testing scans.
Approximate range and azimuth to four gauge networks (based on preliminary locations):
Gauge Network #1
Ji Parana Airport
Gauge Network #2
Gauge Network #3
Gauge Network #4
Fazenda Sao Jose
Preliminarytiming on scan sequences:
Meso dd e (135° )
Meso dd w (135° )
Meso hires (90° )
Gauge 2,3,4, toga (27° )
Loop far polsec (120° )
Loop near polsec (120° )
Loop survey (360° )
Gauge 1 (27° )
1745-1756 Vertically pointing scan. Zdr of by 0.2 dB.
January 14, 1999
0026 Stopped, reset PMAC. Restarted loop survey (TRMM4.SCN) RHI through cell @ 139
0038 RHI through cell @ 180° , 42 km (Note times for RHI’s are times scans were set, not times scans actually occurred).
0049 RHI now @ 146° through two cells 93 km and 120 km.
Note: Convection this shift has not been very exciting; Little at or above 40 dBZ now.
0130 Convection very bleak now.
0220 Changed RHI for cell @ 190° , 70 km (stretching here; there is just about nothing to scan).
0231 Think that cell is AP or something; Vr and MP variables are off, plus it’s only on 0.5° scan. Switching RHI back to 149° for debris there.
0301 Recommend eliminating RHIs during dead periods; switching to pure surveillance scans (0303).
Note: Need to run "loop survey" sequence instead of survey alone to maintain 10 min cycle.
January 15, 1999
16:00 Radar repaired! Need to check it out for a few minutes and then we'll be operational.
16:17 Operational. Running "SURVEY" 360
Added 2-tilt 360° to trmm4.scn. Approximate azimuth from S-pol to TOGA: 323° S-pol relative.
1640-1700 Trying to contact TOGA unsuccessfully with cell phone. Couldn't get through.
16:56 Started loop survey. RHI centered at 180° . Nice bright band to south in all polarimetric variables. Beautiful RHI's through bright band to south. LDR is enhanced real nice; just offset below Zh. Bright band centered at 5 km. Nice fall streaks beneath band.
17:10 Still unable to contact TOGA. Zdr,F dp, and r hv seemed to be more enhanced in the weaker part of the bright band (closer to radar R = 30 km). Part of bright band with fall streaks has less interesting (less enhancement) in LDR, Zdr, F dp, and r hv.
17:30 Weak shallow conv. in center of east lobe. Can't get in touch with TOGA to practice DD times.
17:51 Running far polsec (up to 17° ) loop (120° sector) centered on 32° relative to S-pol....shallow. RHI centered on 32° . Shallow convection to NE covering with far polsec loop.
SCAN FILE CHEAT SHEET
trmm1.scn: meso dd e loop
meso dd w loop
hires dd (90° ) loop
trmm2.scn: gauge 2,3,4,toga loop
trmm3.scn: far polsec (120° ) loop
near polsec (120° ) loop
trmm4.scn: survey loop
trmm5.scn: gauge 1 (airport) loop
Note: 2-tilt 360° exists in all five files.
Use 2-tilt 360 for clear-air or "barely any precip" situations. It has a 2-min update so it will recycle about every 10 min.
Use loop survey (trmm4.scn) for general purpose surveillance of widespread precip. Has RHI's if needed.
Use loop meso dd e [w] (trmm1.scn) for dual-Doppler coverage (widespread) in eastern [western] lobes.
Use loop dd hires (trmm1.scn) for more isolated convection in dual-Doppler mode.
Use gauge loop 2,3,4 for gauge/disdrometer studies in networks 2,3,4 or TOGA
Use loop gauge 1 for gauge/disdrometer/profiler studies over Ji-Parana airport.
Use loop far polsec for general polarimetric sectors outside 35 - 55 km in range
Use loop near polsec for general polarimetric sectors inside 35 - 55 km.
Note: for loop survey, far polsec, near polsec, hires dd, gauge 1, gauge 234 you will need to choose azimuths for RHI's. For loop near polsec, far polsec, and sometimes hires dd, you will need to choose the center point of the sector. Try to keep sector size the same to maintain 10-min timing.
If you wish to create your own scans, please save it in a different file. Remember to maintain approximately 10-min cycle on the 2-tilt 360° scan (i.e., all scanning loops should have a 1.1° 360 degree scan every 10 minutes).
18:36 Unable to contact TOGA for last 2 hours.
18:39 Shifted 120 far polsec RHI to center of 55° (NE).
Note: not advised to switch between scan files without stopping antenna first. After stopping antenna, reset PMAC. If everything OK, then open new file and restart scan/loop.
18:50 Finally talked to Nadia at TOGA. They could not call us either earlier this afternoon.
19:19 Switched to 2-tilt 360° which updates every 2 minutes giving 10-min cycle. All convection shallow and at R ³ 60 km.
19:20 Shut down flat plate.
20:06 Running loop far polsec on cell centered @ 75° , 72 km single cell w/ scattered debris cells. Fairly shallow, but exhibiting heavy rain on particle ID and it's the only thing around. 30 dBZ to about 6 km, top @ 15 km. Peak Zh > 50 dBZ.
20:26 New loop. Shifted RHI center to 77° to account for motion of storm. Mostly mod. rain in main cell according to particle ID.
20:36 New loop. Small cell popping up in sweet spot of E. lobe. Covered by sector. Possible D-Dop?
20:50 Main cores mostly up to 5-6 km.
21:02 Cells in D-Dop lobe centered around 32° , 81 km S-pol
78° , 81 km TOGA
Going to try to raise TOGA; cannot call TOGA; will try after sunset, see if that helps.
21:11 Lot of new small cells in E. lobe. Too bad our cell phones (don't work).
21:14 S. Convection collapsing. Switching RHI to 54° at R = 65 km to cover new cell. This loop shift polsec to 60° centered to cover more of the newer convection next loop.
21:22 New loop started with aforementioned changes; may want to shift even more next loop as cells extend beyond W. boundary of scan. Will switch center to 30° next loop.
21:27 Numerous small cells popping to N w/in 40 km; nothing too special yet.
21:43 Shift PPI W 10° (center 20° ) next loop to cover more of cells just to our North; Shift RHI to 55° next loop too.
Action Item: Comm. w/ TOGA. Sat. phone available but is very expensive. Steve and Larry need to arrange something w/ TOGA as they are well aware.
21:54 Still not impressed with close northern cells to switch to near polsec.
22:01 Switched RHI to 57° .
22:11 Rotating RHI to 7° to cover small but intensifying cell @ 51 km; Near cells still very tiny and judge it not worthwhile to start FCM. In fact, nothing out there right now is all that exciting.
22:16 RHI shows cell to have 45-50 dBZ up to 5 km; tops about 11 km.
22:18 Everything being scanned right now is pretty small, and has been for some time; RHI shifted to 9° for storm motion.
22:31 Rotating RHI to 63° this loop to cover developing cell @ 30 km; see if it's worthwhile shifting polsec & running FCM.
22:35 Cell has 40 dBZ to 4-5 km, tops to about 8 km; Think I'll hold off on going crazy with scan shifting right now. All in all, convection right now is barely worth a polsec; very popcornish, nothing big, nothing sustained; might be worth a meso dd e due to widespread nature, if we could actually communicate with TOGA.
22:50 Switching RHI to 15° to cover northern convection @ 45 km or so again.
22:54 Northern cells have anvils to 12-13 km with main cores below 6 km.
23:00 Shifting RHI to 29° to cover new cell @ 48 km; shifting polsec to center on 30° next loop to cover close convection better.
23:03 New cell looks much like the others in vert. structure, maybe a bit higher in Zh. Still not very exciting.
23:14 Shifting polsec center to 40° to accommodate near convection.
23:18 Decaying stratiform grazing north end of airport gauge network. RespectableF dp shifts.
23:20 Stopped; will run gauge scans on network #1.
23:24 Started net #1 gauge scans (trmm5.scn) centered on 23° .
23:28 Particle ID has light to mod. rain at gauges; more at NE gauges than @ SW gauges.
23:34 N gauge still out of heaviest rain; Will switch back to polsec after this next loop.
23:43 Stopped antenna.
23:45 Restarted far polsec loop centered on stratiform/decaying convection @ 25° , 50+ km.
23:50 RHI shows bright band in this convection; Will shift PPI 15° to 40° center to cover more of near (< 40 km) convection to east.
23:56 Will switch to near polsec centered @ 90° , 35 km next loop to cover developing cell started FCM; Switched RHI to 90° this loop; Although looks like far polsec is topping it OK.
January 16, 1999
00:01 Peak Zh in E. storm >50 dBZ, w/ most of core below 6 km; some spots up to 7 km.
00:05 Stopped; Started loop near polsec on 90
00:13 Main core extends up to 9 km in places, now about 25-30 km out. Hydro ID shows graupel above melt level.
00:25 Switching RHI to 95° to accommodate motion, flank development. Main core crossing over 20 km range ring toward S-pol.
00:28 Movie shows this cell to be about only thing in town.
00:32 RHI shows main cores < 5km AGL; probably why no lightning seen on FCM
00:42 Convection clearly decaying not much else out there to take its place.
00:53 Everything dying out.
00:54 Stopped; now running 2-tilt 360° surveillance as of this time.
04:23 Still in 2-tilt 360° mode. Nothing of interest. One small cell at about 90 km 141 Az with 40 dBZ. However, there is still a clockwise rotation evident around the radar.
05:00 Some convection evident at 98 km, 318° . It's stationary as cell develops about 15-20 km south of rain gauge #4 still in 2-tilt 360° mode.
05:30 General widespread increased returns in eastern hemisphere but echoes are less than 30 dBZ.
06:04 Running 7-tilt survey scan.
06:24 Running 2-tilt 360° .
06:46 Running high res. loop. Looking at cell @ 90 km 318° . Has high 40's dBZ, wide spread and interesting BWER. RHI should be through that BWER. Center of PPI sector at 335° so that rain gauges are also covered.
07:06 Back to 2-tilt 360° 's. BWER continues but cell is shallow and PPI sector scan was wasting time scanning clear air.
07:13 Running jaRHI through BWER. Cloud tops about 10 km.
07:31 Running 2-tilt 360° . General widespread echoes are increasing with most regions less than 35 dBZ. Only a few pixels greater than 40 dBZ.
07:45 Running 7 elev. angle survey reflectivities build to about 40 dBZ and then stall.
08:38 Running RHI through largest cell at 58 km, 313° AZ. Can see Zdr, LDR BB.
08:43 Running 7-tilt survey.
10:08 Reflectivities have been decreasing running 7-tilt survey.
10:33 Running RHI through cell at 310° Az. Some cell has been at about this Az. the entire evening.
10:37 Running survey, 7-tilt.
13:44 Running loop survey (7-tilt) w/ 13 RHI's centered on 67° . There is some stratiform precip. w. embedded cells to east up to 35-40 dBZ at low levels. Checking it out.
Note: Don made some nice icons to back-up and restore our scan configuration. We'll keep the icons in lower right w/ antenna control. "Back-up Scans" and "Restore Scans." Done if something gets goofed up. Just click "restore scans" and it will bring back trmm1-5.scn.
13:50 RHI's 67° , R = 40-60 km. Weak bright band at 4.3 km with some fall streaks in Zh. Nice LDR enhancements. Convection very shallow with 5 dBZ tops around 8-8.5 km.
14:12 Low 40's dBZ in bright band. LDR enhancement. Some fallstreaks evident.
Note: Let's attempt to call TOGA within the first hour of each shift to check comms. and verify each radar's status. TOGA will call us at their changeover too. For now, they will call us at.
14:41 Rotating RHI's to a center of 80° . Could see enhancements in all polarimetric variables in bright band (RHI's). Zh = 35 40 dBZ, Zdr = 1.5 - 3 dB, LDR = -18 to -14 dB, r hv = .85 to .95, F dp: intermittent jumps to 5-20° .
15:01 Rotated RHI center to 85° . Still running loop survey. Westerlies up to 2 km and easterlies above. Nice shear in Vr.
15:09 Turning off transmitter for 5 secs to check something. Loss of data < 30 sec, just a few rays (30° or so). Shallow precip. to east is moving almost due south. Tops still around 8-9 km. Very cool outside with cirrus overcast reducing diurnal insolation.
15:20 Rotated RHI's to 90° center.
NOTE: TRMM satellite overpasses and their times are posted next to the maps. At a minimum, let's make sure we're running the survey scan or something with more tilts when satellite comes over. If you're in a special scan (DD, gauges, polsec, aircraft), keep doing what you're doing.
15:30 Lot's of nice bright band RHI's. Seeing some +Zdr's and +D F dp well above melt level (7-9 km) that suggest oriented crystals that later aggregate and give us the bright band features. Checked grad(Zh) in +Zdr regions. Several +Zdr areas looked real. (little or no Zh gradient). +Zdr: 1-2 dB; +D F dp 10-30° over 20 km + range (0.5° km-1). Let's get the Citation in this stuff! Interesting r hv minimum in the shear zone between low level westerlies and easterlies above. High s hv due to turbulence and shear would reduce r hv (if non-Gaussian spectrum??). Verified that s hv is high with r hv min. (4 £ s hv £ 7.5 m s-1 in shear zone).
16:00 Shifted center of RHI's to 100° .
16:30 Shifted center of RHI's to 110° . More and more of the same signatures in precip.
16:54 Shifted RHI's to 120° center.
17:00 Some popcorn convection w/ max Zh up to 45-40 dBZ at 2.5 to 3 km AGL. Convection located R = 40-60 km to NE (30° -45° ) and also to south R = 80 km.
17:22 Stopped antenna. Running 2-tilt 360° while editing dual-Doppler scans in trmm6.scn (new file). Creating "DD" far: meso dd e/w far: chopped at 15.8° (T=327 sec). hires dd (238 sec).
17:40 Stopped antenna. Restarted the new scan. Testing "mesofr dd e" in trmm6.scn. Testing time at 10 min. Not much for RHI's to loot at. Very, very shallow. Need to firm up times on trmm6.scn.
18:42 Stopped test of meso far dd e. 18:42:32 started 2-tilt 360° temporarily. Will practice meso (135° ) dd east with TOGA. We will start scan at 1850. Using file trmm1.scn, loop meso dd e near. Stop 2-tilt 360° @ 1849:20. Start loop meso dd e @ 1850:00 +/- 2 s. 1900:00: finished cycle darn close to 10 min...will need to check file to verify.
Note: Dual-Doppler Synchronization Policy: If timing is lost and DD still looks good and comms. are lost, always reset on a ten minute cycle (i.e., ten past hour (xx10), 20 past (xx20), xx30, xx40, xx50). If communications available, re-check synchronization via cell phone about every 30 minutes or so (3-cycles).
19:30 Stopped testing meso dd e near. Re-started loop survey. Not enough targets close in. Stopped loop survey and restarted 2-tilt 360° .
21:25 Stopped antenna.
21:26 Starting loop survey; RHI on developing weak line of convection about 125 km @ 32° . Far away and not too strong, but organized. Makes it work at least a full survey w/ an RHI also some slightly org. convection about 90 km, 225° (centroid).
21:31 4-5° tops just about everything.
21:36 Most everything's under 5 km in the NE line; will switch RHI to SW convection next loop.
21:39 RHI will be centered at 224° , focusing on small cell @ 75 km; however another cell is @ 236° , 65 km; rest is debris/stratiform in that region.
21:46 S-pol had a tape-writing problem; unclear when it started or if data were lost. Not much out there so not a complete disaster. It is all working now.
21:50 RHI will be @ 234° to cover the other aforementioned cell; everything is very weak.
21:51 There is definite organization going on out there but it's all very shallow,£ 5 km mostly; given range, low peak reflectivities and shallowness, sectors not advised.
21:55 OK, now I see some stuff w/ 45-50 dBZ in it, tops to 6 km, in RHI.
22:05 Stopped recording due to tape drive mixup; need to fix it real quick.
22:14 Restarted recording.
22:19 This loop RHI shifted to 226° to account for motion.
22:24 Attempt to raise TOGA for D-DOP practice fails; will try again later; RHI shows storm£ 8km all told.
22:28 RHI shifted to 224° for motion given shallowness of storm, I suggest holding off on polsecs; It is about 45 dBZ max; not too bad for today, but clearly not worth making a case study out of it. Besides, high tilt 360's gives us more comprehensive coverage of other cells; new one due west @ 60 km, not as strong yet.
22:38 RHI shifted to 218° for storm motion.
22:52 Shifted RHI to 214° .
23:11 Things dying out now; may shift back to solely 2-tilt 360° after this loop; sunset really killed everything.
23:20 Stopped; restarted 2-tilt 360° .
January 17, 1999
02:29 Have tried to reach TOGA a few times over last few hours. Getting lots of beeping, no Portuguese message; maybe it's busy or something; maybe will try once more before shift changes.
03:37 OK, been unable to raise TOGA. Comm. w/ them may be possible w/ current cell phone setup, but it is unreliable to say the least.
05:38 2-tilt 360
06:40 Continue 2-tilt 360° scan. A few cells are appearing in the western hemisphere of the display. 30 dBZ is about max.
07:59 Running 7-tilt survey scan.
08:06 Back to 2-tilt 360° mode (yawn).
09:16 Running 7-tilt survey.
09:24 Running RHI @ 310° Az. Cloud top about 8 km.
09:31 2-tilt 360° . Some cells have 40 dBZ peaks in them.
09:48 Running RHI, center @ 274° Az cloud tops about 8 km. 45 dBZ core.
09:54 Running dd w. Can't reach TOGA radar with cell phone. Cell movement is to east in upper hemisphere to the west in lower hemisphere.
10:07 Running far polsec scan centered at 270° AZ. Good cell at 245° AZ @ 55 km. Has BWER. Cloud top to about 10 km. Wind shear at about 4 - 5 km with negative V at ground (-9 m s-1) and positive V above (about 4 m s-1).
10:14 BWER @ 5° elev., 55 km range, 253° AZ
10:28 Continuing pol. sec. scans
10:32 LDR (enhanced) marks region of shear.
10:47 Still running pol sec. Cell at 245° AZ still has 40+ dBZ. Other cells up north have weakened. Circulation is evident especially at higher elevation angles.
11:01 The shear at 5 km through the cell is about most interesting thing. One area @ 45 km had cloud top at 12 km. With increasing height the velocity again went negative and then positive at cloud top. Peak Z's are 42 dBZ.
11:20 RHI @ 195° looking at cell 20 km away (still using pol sec loop).
11:32 Can see very distinct LDR BB in RHI @ 5 - 6 km AGL. Can also see BB in Zdr andr hv with Zebra.
12:34 Changed center of 120° far polsec to 225° to capture shallow convection to SW better. Shifted RHI's to 244° .
Note: Put height vs. slant range table on inside of back cover of log book.
Note: Lost full matrix data during daylight hours yesterday. Tape problems. Typical dual-polarimetric fields were recorded.
13:21 Most precip to southwest topped at 8° -10° elev. Therefore, will switch to 7-tilt survey loop which goes up to 9° . Stopped farpolsec and started loop survey 7-tilt 360° .
13:24 A few isolated "popcorn" cells to ENE (65° ). Tops around 5.5 km. Max dBZ 40 - 45 dBZ.
13:30 Tried to contact TOGA unsuccessfully for 10 minutes on cell phone. Will try again later.
13:40 Precip. to SW is mixture of decayed convection with bright band and lumpy embedded shallow convection. Interestingly, there is more phase shift (positive) above the bright band them below. Hydrodynamically oriented ice I would guess. Zdr's in this region are on the order of 0.5 to 1.0 dB.
13:43 More isolated convection popping up between 30° - 90° in Azimuth and R > 30 km. This popcorn convection is in the southern portion of the eastern DD lobes and quickly heading out of lobe toward east-southeast (ESE) moving at 9 m s-1.
13:54 Some 45 dBZ toward NE (35° ) at 35 km in range.
14:03 Cells to E-ENE (30° -90° ) are multiplying.
14:16 Rotated RHI's to center @ AZ 50° to look at developing convection. Peak Zh is 50 dBZ. Tops at 7 km.
14:25 Rotated RHI center to 60° . 360° surv. not topping cell to ENE. RHI's are covering vert. structure. After 1.1° tilt in 360° , will switch to sector (farpolsec) nice RHI's through isolated cells at R=30 - 50 km and AZ of 54° - 66° .
14:35 Stopped survey. Started farpolsec (120° ) centered on 75° AZ with RHI's centered on 65° .
14:48 Rotated RHI center to 68° . Tops around 7 - 7.5 km still with 30 dBZ pretty much below 5 km. Peak Zh of 52 dBZ down low at 2 km or so.
15:00 Rotated RHI center to 75° .
15:16 Rotated RHI center to 85° .
15:25 Down for maintenance.
15:46 Back on the air running 2-tilt 360° to see what's going on.
15:52 Stopped 2-tilt 360° and started survey loop. Centered RHI's on 234° to SW to look at cell with D F dp significant @ about R=27 km. Over five cells in RHI. Cells to S-SW-W. 1) stratiform with 14 km tops at ranges > 60 km. 2) isolated cells with tops to 5-7 km. 1 cell new to NNE R = 18 km. 1 new cell ENE R=25km. Cell within 20 km. Flat plate is running. Tops 7 km.
16:08 RHI's centered on small cell 17 km to NNE @ AZ of 30° . Got good high resolution sample in the vertical of most of the cell.
16:17 Center of RHI's at 172° ; interrogating small developing cell to SSE at R=12-15km. Zh max = 50 dBZ. Zdr max=2.5 dB in core 2-4 km AGL.
16:27 Saw some Zh of about 55 dBZ in cell to SSE (AZ of 155° ). Rotated RHI to 155° . Bit of phase shift, Zdr = 1.5 - 2 dB, Zh = 50 dBZ.
16:35 Shifted RHI's to center of 229° to look at mature convection to SW. This feature has persisted since persisted since before shift change. Mature precip. system to southwest looks oceanic or monsoonal in that it has tops to 14 km with 30 dBZ embedded cores with tops to 5-6 km.
16:55 Shifted RHI center to 201° . AZ 206° -207° : 50 dBZ max, 2.5 dB Zdr max, and some diff. phase.
17:04 Going clockwise, scattered popcorn showers from 270° to 330° , isolated showers from 310° to 60° , scattered popcorn from 60° to 180° , from 180° to 270° there is widespread precip. (same place as 1230 UTC this morning). Many isolated cells have max Zh from 50-55 dBZ, max. Zdr from 2 - 2.5 dB, and most 30 dBZ tops < 6 km.
17:09 Rotated RHI's to small cell R<30 km to SE (107° ). Tops to 5 km. Lots of warm rain cells today. No flashes that I saw on flat plate (should double check).
Note: Unable to call TOGA all day. It is difficult to even get a signal with a cell phone at the S-pol site. Cell phone comms. are a nightmare. Must find alternative!
17:18 Frequency of popcorn convection increasing. Good day to check for warm rain lightning at R < 60 km. Rotated RHI's to 342° to look at compact isolated cell with Zh > 50 dBZ at range of 40 km or so. Tops about 9 km.
17:26 Shifted RHI's to center AZ of 194° . Edge of system to SW. Couple of boundaries merged in vicinity earlier. Tops 9-10 km. 30 dBZ tops generally < 6 km; a few pixels poking upward above 6 km.
17:40 Shifted RHI's to 122° to SE to look at isolated cells. Tops @ 6 km. 55 dBZ max reflectivities, Zdr > 3 dB according to Zebra There are peak Zdr of 4.5 dB about 1 km below peak Zh of 55 dBZ.
17:47 Shift AZ center to 185° to look at series of isolated cells.
17:59 Shifted RHI AZ to 315° to precip. very close to radar.
18:00 Saw pixel Zh» 59 dBZ.
18:02 Raining at radar; too intense for vertical pointing.
18:08 Stopped antenna.
18:15:47 Running vertically pointing mode. Some too saturated but some OK. Looks real good. (Zdr) very close to zero.
18:16 Switched back to loop survey. Some isolated cells are loosely organized in long lines (» 100 km). Been that way for couple hours now. Nice example just south of radar at 18:20. It passed over radar.
18:21 Centered RHI at AZ 120° through part of line. Lots of small isolated cells, R > 30 km. Cells at R< 30 km has decent phase shift » 0.5 ° km-1. Zh > 50 dBZ, Zdr » 2 dB. More phase shift in general now (heavier rain!). Interesting in blocked sectors to west where there was significant phase shift unaffected by partial blocking while Zh was significantly reduced.
18:33 Audible thunder. Saw transient on flat plate. (times approximate). 18:35 audible thunder. Cell right overhead almost. 16 km tops with 35 dBZ > 9 km in height.
18:34 RHI's centered to south. Scanning up to 85° elevation angle. 16 km tops.
18:42 Running 2-tilt 360° .
18:46 Stopped 360° . Running RHI's to 60° elev. angle centered @ 128° AZ. Cell not as deep.
18:52 Stopped RHI's. Running loop survey with RHI's centered 135° . Interesting how one cell punched into mixed phase and produced lightning. A bit too close to radar for ideal case study but neat none-the-less.
18:59 Cells interrogated by RHI's have some 35-40 dBZ to above -10° C. R » 20-35 km. Rotated RHI's to center AZ of 118° . Cores seem quite tilted at this time. Tilting toward radar (to NW). Low level reflectivities approaching 55 dBZ at 120° AZ. Most 30 - 50 dBZ at heights < 6 km, occasionally 30 dBZ core punches above 6.5 - 7 km. No real precip. over gauges so far today. Still cannot reach TOGA. Very difficult to get signal and when I do I can't get TOGA. Rotated RHI center to 114° . Isolated popcorn in northern half and more organized to south.
19:48 Changed center of AZ to 53° to look at small cell to NE.
19:58 RHI's rotated to 120° .
20:06 RHI rotated to 109° this loop.
20:15 RHI to 117° this loop still widespread convection shallow and mostly outside of 60 km RR.
20:46 Shifted RHI this loop to 38° to examine developing cell @ 60 km. Lot of popcorn convection in E. lobe. This is one of those cells.
20:57 Switched RHI back to far storm along 118° ; other storm was pretty shallow; nothing worth sectoring right now.
21:18 Shifted RHI to 64° to cover that NE cell again - It has managed to hang around for awhile. Not much else besides these two storms.
21:26 RHI to 69° as cells in storm backbuild.
21:36 RHI to 72° for movement.
21:43 30 dBZ³ 7 km AGL, will start polsecs next loop
21:47 stopped, started loop far polsec on NE storm, centered on 74°
21:54 Peak Zh > 50 dBZ, 30 dBZ > 10 km in height in places.
21:55 RHI to 77° due to motion, storm » 80 km out.
22:04 30 dBZ > 12 km AGL now; too bad too far away for either FCM.
22:06 RHI to 80° for motion this next loop. This is a really nice storm; great vertical development; high Zh; haven't checked MP variables yet.
22:13 MP Particle ID shows heavy rain, Zdr's up to 4 dB or so.
22:17 RHI to 82° this loop.
22:27 RHI to 87° this loop; storm appears to be weakening and growing in areal coverage.
22:38 RHI to 85° this loop; storm consists of two main cells now; RHI through N. cell; still appears to have weakened somewhat.
22:57 RHI to 88° ; storm now a shallow line along this radial or thereabouts W. edge about 90 km, so may switch away from this cell back to surv to see what else may be worthy.
23:06 RHI to 89° for motion. NW cell of interest is weakening & has less rain will stick with east storm for now.
23:12 Seeing significantY dp shift aloft in RHI.
23:16 RHI to 305° to check on storm @ 60 km this loop.
23:21 RHI shows forward cell not too bad, shallow though (< 7 - 8 km).
23:25 Stopped, restarted loop far polsec on NW storm @ 305° , 60 km.
23:36 OK, we are officially missing a halfway decent D-DOP case due to poor communications with TOGA. I can't even call Steve R.'s phone at the hotel. The storm in question is a bit off the baseline in the W. lobe, on the N. edge of the major block. Tops to 15 km, 30 dBZ to about 8 km or so. Thought about using sat phone but we need dialing info. for it.
23:44 FCM (field change meter) started.
23:54 Storm now touching baseline, forms a small SW-NE line; switched RHI to 294° to cover strongest cell on S. end of line; storm is just gonna miss gauge network #2.
January 18, 1999
00:00 RHI shows shallow cell, tops at 6-7 km, but very intense; Peak Zh @ 50+ dBZ.
00:04 Stopped; restarted loop w/ near polsec centered on 315
00:11 Vert. development is intense but shallow, likely under the threshold for electrification, as FCM seems to be showing.
00:15 RHI this loop on 335° , E. edge of line.
00:23 Changed PPI center to 325° next loop.
00:24 RHI to 340° to cover most intense portion of line; left edge of sector clipping W. edge of line; shifted PPI a bit too much I guess. May need to switch to like surv scans due to proximity and size of storm.
00:32 30 dBZ to 7 km or so; switching PPI to center on 320° to prevent some of the clipping.
00:35 RHI to 354° to maintain on strongest cell. Beautiful RHI's last loop; still clipping on W. edge a bit; less linear now.
00:40 Lucked out, w/ storm basically on baseline D-Dop wouldn't be a good idea.
00:42 Zdr's not spectacularly high, about 2.5 dB at peak.
00:44 Running survey loop w/ RHI now due to proximity. Rain @ S-pol. RHI @ 354° , as good as any about now; windy @ S-pol too.
00:56 RHI to 213° to cover S. portion of storm.
01:02 PRECIP ID & MP variables suggest widespread light to moderate rain within 40 km of S-POL; RHI shows shallow convection.
01:07 RHI this loop to 200° to continue monitoring S. portion of storm.
01:10 Drizzle to light rain now @ S-pol.
01:19 Switched RHI this loop to 40° to cover N. portion of storm. Again, airport network just missed this storm.
01:24 Convection in N. weakening
01:28 RHI this scan to 193° to cover portion of S. convection; everything is widespread now.
01:39 RHI to 156° to cover strongest portion of S. convection
01:48 RHI to 143°
01:58 RHI to 151° ; S. convection about the strongest thing around right now, but still pretty shallow and nondescript.
02:58 Switched RHI to developing cell at 44° , 75 km
03:02 Attempts to reach TOGA for possible D-Dop. ops on convection in E. lobe fails.
03:06 RHI reveals yet another shallow cell, mostly under 6 km
03:08 RHI to 48° ; NE portion of E. lobe is main center of activity now, but still nothing much above 6 km, apparently.
03:19 RHI to 59° as storm builds on forward flank; another batch of cells closing in E. lobe from N.
03:28 RHI to 353° to focus on next batch of cells » 100 km out.
03:37 RHI reveals yet more shallow convection.
03:41 RHI to 357°
03:49 RHI to 34° to cover developing cell @ 105 km.
03:52 We are missing a D-Dop. opportunity on the widespread shallow convection in E. lobe due to poor comm. with TOGA.
04:10 Running 7-tilt survey. No RHI's. Widespread low echo region across northern hemisphere of display. Few pixels at» 42 dBZ most Zh < 32 dBZ. Cell movement is NW to SE.
05:18 Still running 7-tilt survey scans.
05:25 Running RHI centered at 45° AZ.
05:29 Running 7-tilt survey.
06:12 Running 7-tilt survey with low el. RHI centered @ 55° AZ. Widespread strat. to north and east of radar. Max dBZ about 40.
07:23 Still running same sequence. Another well defined BB @ 64° AZ.
07:51 Status quo. Clouds tops @» 8 km. Widespread strat. with a few pockets of convection. Everything shallow with 40 dBZ about max Z.
08:52 Widespread low reflectivities in the northern hemisphere. Nothing of significance.
09:59 Still widespread stratiform in northern hemisphere with max dBZ of < 40 dBZ. Abandoning RHI scans.
11:13 Running RHI centered at 30° AZ looking at BB (bright band). Cloud top » 9-10 km.
11:18 Running 7-tilt survey. Widespread stratiform region now located more in NE quadrant. Cell have more southerly flow now rather than NW to SE as was a few hours ago.
11:51 Running an RHI centered at» 30° AZ even BB signature is weak now! Max. dBZ £ 30.
11:54 Running 7-tilt survey.
12:20 There is a "bullseye TRMM overpass" today from 1551 - 1605. It will be over the radars around 1554 (descending node). Strategy: Run pol. 360° or sector to try and top whatever is within range of radar. In addition (if possible), throw in some high elevation 360° PPI tilts if there is precip. within < 10 km or maybe <20 km.
12:35 Unable to raise TOGA with cell phone. Tried for 5 minutes. Cell phone network is still screwed up.
13:00 Stopped 7-tilt survey and restarted "loop survey" with RHI's to NE (45° ).
13:50 Stopped loop survey. Running 2-tilt.
13:53 Running rain gauge loop #2. There is some light rain approaching gauge network #4 to NW so I'm sampling to get some experience. Note that gauge sectors are at 0.7° and 1.2° to get a bit above the partial blocking. Rain is light. Not a great case really.
14:30 Rain is very light now. Drizzle almost.
14:33 Terminated gauge 2,3,4 sector and restarted loop survey. RHI's 60° .
14:35 "Blob" of weak, shallow, widespread precip. to NNW (330° ) and NE (60° ). Isolated to scattered weak/shallow precip. to south (90° -120° ).
14:49 Shifted RHI's to NW (324° ).
14:57 Shifted RHI's to NE (57° )
15:10 Could do DD in eastern lobe (far) but cannot contact TOGA with cell phone. Will stop survey and restart at 15:20 to synch up with TOGA in survey scans at least. We are topping most precip. with 9° elevation angle.
15:20 Restarted loop survey.
Note: TOGA restarts a ten-minute scan cycle "on the tens" 00, 10, 20, 30, 40, 50 minutes past the hour. Unless otherwise requested, they're doing 360° PPI's with a few RHI's. Since they spin faster, the actually have higher tilt angles in their 360° surv. So, theoretically, we could do a half-baked synchronization any time we want. If convection is very close to TOGA (R < 30 km), they may not be topping. Otherwise they probably are. So, try this method if another DD opportunity arises without communications to TOGA. "RE-SYNCH ON THE TENS."
15:28 More high Zdr in ice above freezing level. Data looks bad in some spots (highÑ Zh) but looks good in some spots. Zdr is 0.75 - 1.50 dB (some 2) above and 0.4 - 1.0 dB below freezing level. Weak bright band.
15:32 Widespread, weak shallow precipitation to north. Very disorganized (chaotic). Similar but more scattered to south.
15:41 TRMM overpass. Stopped 7-tilt survey/RHI loop. Started at 10:25 long 360° PPI with 0.5, 1.1, 2.5, 4, 5.5, 7, 9, 11, 13, 15, 30° elevation angles. The last high angle is for Dr. Chandrasekar at CSU/EE but this case is less than ideal. I'll try it once and remove it. Running 30° angle @ 15:51 or so. Could be some drizzle in the high tilt angle. During overpass, some light rain in gauge network #1 (airport). This overpass is a bust. Will restart loop survey @ 16:20 to synch up with TOGA.
Note: I created a "SURVEY 2" that lasts about ten minutes (595 sec) that you can use for general surveillance without RHI's. It goes up to 15° .
16:34 One cell has high Zdr (2-3 dB) and some phase shift. About 135° .
16:40 RE-synched. Running Survey 2. Cell to SE (135° ) R» 75 km is still most intense. 38 dBZ up to about 7 km.
17:13 Echoes looking more convective (cellular) to south. Bright band features in LDR, Zdr,F dp, r hv to east. Not as obvious in Zh. This could be "polarimetric bright band" in decaying convection.
17:23 Cell to south producing moderate rain Zdr» 1-2 dB, D F dp is evident in 2-3 cells. Considering far polsec to south: 120° -240° outside of DD lobes and gauge networks but cells are most interesting.
17:30 Stopped "Survey 2." Started loop far polsec. Cell @ AZ. 190° , R» 55-60km has Zhmax » 53-55 dBZ, Zdrmax » 2.5 - 2.75 dB, evident phase shift.
17:46 Zdr column of 2-3 dB up to 3-4 km Zh > 50 dB, measurable phase. Cell toward 190° continues to have Zhmax» 53 dBZ and Zdrmax» 2.5 dB and good phase shift at low levels (about 2 km). Tops to 7-8 km (cirrus above that at 9-10 km).
17:55 Above features still there up to 3.5 km. Zdrmax» 3 dB.
17:59 RHI's centered on 188° . Very broad area of moderate reflectivities to the east at R > 90 km (45° - 135° ).
18:10 Rotated RHI's to 175° . Convection to south is moving outside of 60 km.
18:19 Stopped loop far polsec.
18:20 Re-started loop survey in "synch" (+/- 3 sec) with TOGA. RHI's centered on blob of precip. to east @ AZ of 68° . No obvious polarimetric bright band. A lumpy Zh bright band. Low level winds veered during the day from 320° (NW) to about 30° or 40° (NE). There is a backing profile with height.
18:32 Rotated RHI's to weak convection over TOGA to have a look.
18:53 Rotated RHI's to 160° .
19:40 Restarted running "Survey 2" 10 min surveillance scan (No RHI).
21:27 Too nice outside and too clear on the radar screen to be inside.
23:14 Severely clear out there.
January 19, 1999
04:22 Running 7-tilt survey with RHI. A few weak cells are appearing in the NE. Appear to be moving S-SE. Max dBZ less than 40. Some 40+ dBZ in BB.
04:27 Small cells are popping up across the entire display area. Can see a rotation signature at top of cell
04:29 RHI scan reveals nice BB. 8 km cloud tops.
05:20 Continuing 7-tilt survey with RHI centered at 214° AZ. RHI show nice BB cell at 35 km. Cloud top » 8 km. Scattered activity/small cells across radar scan area.
06:04 The limited activity is subsiding. Running 10-tilt survey scan and No RHI. BB today marked well by enhanced reflectivity today (i.e., 12 PM - 8 AM shift). The previous two day LDR was a better indicator and the Z BB was not very visible or undetectable even though there was a very good LDR BB.
06:14 Running 2-tilt survey scan.
08:00 Just a few isolated cells with less than 35 dBZ.
08:12 Running 5-tilt angle survey loop.
10:27 Running vertical pointing scan. (EDITOR NOTE: NOT vertically point angle; list incorrect). Very, very light rain at radar.
10:30 Running 5-tilt survey. Just scattered weak activity.
11:05 Running vertical point» 60 sec. (EDITOR NOTE: scan list not correct; not an acceptable vertically pointing scan).
11:07 Back to 5-tilt angle survey scan. A few cells now south of the radar.
11:26 Running loop survey with RHI scan. There is wide spread echo region south of radar within 40 km.
11:33 Running RHI centered at 234° AZ. Another nice BB. Cloud tops at 7-8 km. BB at 4-5 km. Maybe Zh reached 45 dBZ in BB.
11:44 RHI centered at 234° AZ.
NOTE: I forgot to mention that a vertically pointing scan designed by Jon Lutz is in "brazil.scn." 3.5° s-1, 256 samples, various elev. angles » 90° , » 2 min. long. Use when light rain or drizzle overhead. Grab every opportunity if possible.
12:10 Running solar calibration. Will be down for 1 - 2 hours. Power fluctuated by» 0.01 dB. Pretty good.
13:26 Radar is back up now. Running "Survey 2" which is a 5-tilt 360° PPI repeated twice every ten minutes. (5 minute per volume). No RHI's.
14:25 Isolated cells with tops£ 6-7 km. Peak Zh » 30-32 dBZ. Yippie. Westerly @ surface. Above surface, veers low level winds out of NNE. Lots of blue sky there. Muito heating. Let's hope we're prepping for deep convection late afternoon. Otherwise, it's a yawner.
15:39 Continued isolated to widely scattered weak to moderate, shallow cells. Tops to 5-6 km, Zh < 30 dBZ. Easily topping everything within Rmax with 5.5° .
NOTE: Partial blocked to west at 0.5° and a little at 1.1° at Azimuths: 250° -315° . Partially blocked 1.1° still badly blocked between about 255° and 270° .
16:22 Only few weak showers about. No signs of development yet. Still hopeful that something will fire with this good heating.
16:58 Stopped Survey 2.
16:59 Started 2-tilt-PPI while working on gauge scan in trmm7.scn. This will cover all gauges at once with no RHI's.
trmm7.scn: 1. all gauges: 80° PPI, right AZ 37° , left AZ 317° ; AZ rate of 5° s-1; samples of 128, approximate time of 481 sec, beamwidth of 0.752° . 2. 2-tilt 360° : 117 sec. Real time total: 593 sec.
17:18 Stopped 2-tilt 360° . Start: 17:18:20 testing loop surface net. Stop: 17:28:13.
17:29 Stopped testing trmm7.scn (loop surface net) and restarted "survey 2." The waiting for something to happen scan.
NOTE: trmm7.scn (loop surface net): is ready to go. Use it when there is widespread precipitation over all or most of the gauge/disdrometer networks and/or profiler.
17:38 Scan files backed-up (*.scn).
NOTE: "Unambiguous range" = Rmax = C/(2*PRF)=3x108 m s-1/(2*850 s-1) = 176 km. However, we are collecting full polarimetric matrix data so we are limited to 1040 gates (149.9 m per gate). 1040 x 149.9 m» 156 km, which is our actual maximum range in full pol. mode.
17:58 Still only isolated weak showers about the region. Most echo > 15 dBZ is between 3.5 and 5 km. Weak echo seems to be primarily located just below freezing level. Very little precip. getting to 0.5° to 1.1° tilts. All still £ 25 dBZ.
18:36 Moderate reflectivity (30-35 dBZ) cores popping up distant (R>120 km) NE (30° -60° ).
18:39 40 dBZ max! at R» 150 km. What excitement.
19:06 New 40+ dBZ to WSW about 90 km. Died 10 minutes later. Moderate cells still to NE R³ 120km: 40+ dBZ. New cell 120 km to east. I'm desperate for something R < 60 km.
19:46 More widespread very weak Cu/TCu R < 60 (Zh < 10 dBZ). Some cells mod. strength Zh > 35 dBZ. R > 60 dBZ. Mostly to NE: 0° - 60° ; a little to SSW (200° ) little to E. New 40 dBZ cell to west (268° ) R=70 km.
20:10 Widely scattered moderate showers, popcorn cells. Most intense still to NE R³ 120km. Small cells 60 km west. Lots of weak popcorn TCu Z< 10 dBZ to west.
20:16 Cell to NE (35° ) at R=118 km has tops to 9 km.
20:20 Most cells R³ 120 km to NE-E have Zh ³ 40 dBZ. Also, cell to west (275° ), R=57 km.
20:22 Cells getting deeper. Will re-synch to 20:30 w/ 7-tilt survey. 50 dBZ in cell to west R=60 dBZ.
20:30 Running loop survey,rhi (7-tilt, RHI's to west, 276° ) after stopping Survey 2. Very high Zdr > 3 dB, 55 dBZ max, in cell to west. Few cells in heart of western lobe. Scattered cells in outer edge of eastern lobe. We're synched with TOGA and appear to be topping all convection with 360° surveillance up to 9° elev. angle. So, I don't have to pick a lobe just yet. Zdr > 3 dB off scale tops 9 km and building.
20:57 Just barely topping cell to west with 9° elev. angle, 11-12 km tops. Decisions, decisions. Cells to NE are more numerous but at long range. Cell in west lobe is closer but in partial blocked region. Stuff in east lobe is moving toward baseline. West lobe cell nearly stationary. Rotated RHI's to 270° to catch smaller cells to WSW. Still topping with 9° .
21:11 Tops to 10-11 km to west (R=60 km). Larger complex (L=30km wide) to ESE @ R=130-150 km.
21:14 Small cell @ R=62 km, AZ=211° has Zh=53 dBZ. Topping 10 dBZ with 9° elev. angle.
21:20 Stuff to west starting to show movement to WSW/SW.
21:24 Shifted RHI sector to 251° to look at popcorn CB’s.
21:25 Big stuff coming in from east. Might be a disorganized "squall line" of sorts. Too far away to tell. Az: 90° -120° . R: 120-160 km.
21:33 Shift RHI's to look at "big stuff"/convective line to east. Center AZ: 102° . Max. elev. angles overkill but will. Huge anvil: 90-100 km stretching to west.
21:40 About 100 km of this MCS/conv. line is now visible on scope to east. Conv. in eastern lobe (R>100 km) is less impressive but hanging together. I'm still topping with 9° . Will re-synch @ 2150.
21:48 Shift RHI to 105° . Will update next time. Nice anvil! Tops around 14 km - 15 km.
21:50 Restarted loop survey to synch with TOGA (within ten seconds or so). Changed max elev. angle on RHI's to 12° to stop scanning clear air so much. Should finish in about 10 min.
21:52 Nice conv. line to ESE with³ 50 dBZ over 40 km long. Something very large is emerging from the east. So far I'm topping convection in far eastern lobe with 9° . May have to make a decision later whether to top eastern lobe or continue to document full structure of MCS to far east. This MCS is south of eastern lobe and will miss with current vector to ESE.
21:58 Interesting cells developing beneath monster anvil to east. See RHI's. Very nice RHI's of leading anvil and distant convective core. +50 dBZ cores developing directly under anvil is fascinating. Finished cycle within +/- 30 sec. of 10 minutes.
22:02 There appears to be convection organized along a huge line (L>150 km) entering eastern side of maximum coverage. Should be good night.
22:07 Topping all except MCS anvil with 9° elevation angle surveillance. There are multiple cores ahead of original line feeding this anvil.
22:10 Re-synched. Rotated RHI's to 108° . Line in far NE part of eastern lobe continuing to develop. Will try to make sure it is topped. 9° still topping lobes. I'm concerned that 2° beam spacing between 7° and 9° is not ideal. Making up 360° surveillance "on the fly." Az. rate: 6.2° ; Beamwidth: 0.93° ; Samples: 128; Simulated time: 595 sec. Angles: 0.5, 1.7, 2.9, 4.1, 5.3, 6.5, 7.7, 8.9, 10.1, 11.3° (1.2° elevation beam spacing). This is now "Survey 2." OLD Survey 2: 6.2° s-1, 128 samples, 300 s, 0.93° , 0.5, 1.1, 2.5, 4, 5.5° .
22:30 Running Survey 2.
22:33 Very respectable cell punching through old anvil @ 105° AZ, R=71 km. Heavy rain.
Just realized I don't have 1.1° scan for NCAR rain accumulation.
22:49 Stopped antenna.
22:50 Re-synched with big line ppi (Az left: 317.5° ; Az right: 182.5° ; Az rate: 6.3° s-1; bwidth: 0.95° ; samples: 128; elev angles: .5, 1.6, 2.7, 3.8, 4.9, 6, 7.1, 8.2, 9.3, 10.4, 11.5, 12.6, 13.7° . Basically focusing to east but still getting surveillance. Synched to within 7 sec.
23:00 Lightning to N-NE 1 every minute or two. Too far for flat plate??. Two centers of lightning. 1. due N., 2. NNE.
23:28 Stuff to distant east falling apart as we loose diurnal insolation.
23:29 Few per minute of in-cloud lightning in convection to North and SE. Heavy rain to North 80 km with cell producing lightning. Easily topping with 13.7° . Could back off and add RHI's. Topping around 12° . Will leave alone for now. Convection in eastern lobe with lightning should be good DD case.
23:41 A bit out of synch with TOGA.
January 20, 1999
00:02 Antenna ramps up every 180
00:10 Running hi-res D-Dop (trmm1.scn) on N. storm centered @ 348° (RHI too). Antenna cooperating now.
00:12 Actually, moving RHI to cover S. storm @ 126° , at least get some data that way.
00:19 N. storm is redeveloping outside lobes, S. storm mostly shallow.
00:25 TRMM satellite overpass. SE quad.
00:29-:30 Stopped to resynch. on 10's; both N. and S. storms weakening; N. storm moving out of lobes. Will start surveys after this loop moving RHI to developing cell @ 95° , 70 km.
00:40 Stopped; started loop far polsec on E. storm, centered on 95° . RHI set on 100° .
00:58 Storm weakening; will switch to surv. scans after this loop.
01:00 Stopped, running survey 2 scan (trmm4.scn)
01:05 Noticed elevation angles on survey 2 were messed up by "big line ppi." Will switch to "Survey loop, RHI" to maintain 10 min resolution.
01:10 Running survey to adjust elevation heights; RHI's are screwed up. Will change big line fixed angle list back to old survey 2 setup. Currently big line is (fixed angle list #4): 0.5, 1.6, 2.7, 3.8, 4.9, 6.0, 7.1, 8.2, 9.3, 10.4, 11.5, 12.6, 13.7°
01:17 Switched survey 2 to 0.5, 1.7, 2.9, 4.1, 5.3, 6.5, 7.7, 8.9, 10.1, 11.3° as a few pages back, will restart on the 20.
01:20 Restarted Survey2 scan.
03:00 S-pol problems stopped scan; like every other ray is garbage (EDITOR NOTE: According to Bob Rilling, data packet loss.)
03:07 Data look fine now; survey2 continues
03:37 Running rain gauge loop (trmm2.scn). Some spotty cells over network #4. Centered RHI's on 327° .
03:45 Probably light to moderate rain at gauges #4.
03:59 No major cores have hit gauges yet, but they are still in echo; gauge scans continue.
04:30 Stopped; main cores weakened & moved away from gauges.
04:31 Restarted survey2.
06:35 She's deader than a doornail out there.
10:32 Some suspended very light strat. precip. to our north; remaining in surveillance.
12:19 Returned Survey2 to original state. Az rate: 6.2° s-1 (0.93° ). Samples: 128; El. angles: 0.5, 1.1, 2.5, 4, 5.5° .
12:20 Re-started Survey2 loop with above angles.
Note: For hydrometeorology (LBA and TRMM) purposes, we should try to make sure there is a 1.1° elev. angle 360° surveillance once very ten minutes. 0.5° is badly blocked and 1.5° -1.7° is getting a bit high. Also, NCAR precip accum. and movie loop looks for 1.1° beam.
12:47 Winds have veered around to SSW closer to surface and SSE to E aloft with backing height. Generally southerly now. Probably correlated with re-emergence of S. Atlantic Conv. Zone. Convection last night. There is an overpass. Will sample SE-W Quad. around 1506Z.
13:20 Made contact with TOGA or cell phone. If the opportunity arises, we will try an intercomparison on an isolated cell or stratiform in baseline or E. lobe. Insure minimal propagation through precip. for TOGA. Compare Zh for relative power calibration.
Note: Let's not do any more PPI's > 180° until Jon Lutz gets back and can fix the problem with antenna controller.
14:15 Isolated weak-moderate Zh cells popping up in SE quadrant along a disorganized line from 180° to 110° . Good for TRMM overpass? Easily topping everything of interest with 5.5° . Line tangent to R=60km. Convection to SE appears to be moving almost due west. Weak precip. (remnants) to NW are moving toward NW. (??) Interesting.
14:40 Weak to moderate cells from E (80° ) clockwise through SSW (210° ) popping up and moving WSW.
14:45 New moderate showers popping up from 270° to 330° (NW). Isolated cells , shallow warm rainers.
1450-1500 Everything is outside of R=60km. Topping mostly. Topping about 10-15 dBZ everywhere. Will leave this scan for TRMM overpass. There is not any precip. within 60 km so high elevation angles are not possible or necessary.
15:00 Cells in NW quadrant showing signs of intensification with Zh up to low 50's dBZ. Cell at AZ 275° , R=105 km, has 38 dBZ up to 8 km. Systems to east are horizontally larger but a bit less intense.
15:05 53+ dBZ in cell to west. Az. 275° , R=106 km. 2-3 dB Zdr. +40 dBZ up to 8 km. In blocked zone to west. makes DD less attractive.
15:06 TRMM overpass. Will switch to "survey" with 2 more tilts.
15:08 Switched to "survey" with 7-tilts to 8.5° will get low level update every 7-min for now.
15:11 57-59 dBZ in cell to west. R=107 km, AZ: 274° . 7-8 km AGL! 40 dBZ up to 10 km AGL! Will re-synch. with TOGA at 15:20. Topping 0 dBZ with 8.5° elev. angles for now. 16 km tops on this cell to west. This cell is in far reaches R>100 km of western DD lobe. In partial block region. Nice cell. Bad spot. New cells popping up at 66° to NE at range of 45 km.
15:20 Re-synched survey. Considering adding more tilts. What to focus on? Convection all over.
15:30 Running meso far DD east. Fixing center azimuth 1534z. Back to 32° .
15:37 WER in cell to NE. +55 dBZ, > 3 dB Zdr.
15:40 Only topping 10 km @ R=40 km. Will have to switch to meso dd e near @ 1550.
15:50 Running meso dd e (near) (trmm1.scn). Should top cells to NE. Synched up on the tens. Let's hope TOGA is running. Cell phone not working. Inmarsat not working. We should be synched. Fingers crossed. Multiple cells in eastern lobe. Complex to NE (45° ) R=35 to 75 km. Saw some 60 dBZ! Flare echoes (?!!!) all over the place. Interesting. Hail!?! Drop freezing making hail?
16:07 Topping just fine for now.
16:10 meso dd east lobe is place to be. Multiple strong targets. Still synched good. Flare echoes, Zh > 55 dBZ, WER, amazing.
16:15 With this scan, we should top 15 km at R=25 km about.
16:18 Topping real nice. I hope TOGA is scanning. Got through to TOGA. They are scanning. TOGA: 1.0° beamwidth, topping to 29° elevation angle. They cycle 360° volume in 8 min. and then long range (low PRF) surveillance, and end with RHI's. 10-min. total. We should be well synched.
16:30 I've been periodically staring at flat plate. No transients seen (no obvious ones). Could be small blips. Convection is within 40 km.
16:40 Still synched to within 30 sec. May want to re-synch. at 165° . There's 40 dBZ up to 10-12 km within R=30 km. Should be flashes on flat plate.
16:50 Running loop meso dd e. Re-synch.
16:54 Saw a flash on the flat plate.
16:58 Topping all but < 15 dBZ anvil within 25 km.
17:00 Synched to within 5 sec.
17:01 Test flat plate - appears O.K.
17:05 Lots of targets in E. D.D. lobe. Solid line straddles southern edge broken line in central part of E. lobe.
17:07 Visual confirmation of CG on flat plate. Not topping within 25 km but everywhere else O.K. Not topping all flat plate lightning cells.
17:16 Bow echo.
17:30 Re-synched with TOGA.
17:36 Squall line moving west-southwest 40 km h-1.
17:40 Synched within 5 sec. Broken squall line south of E. DD lobe stretching into lobe. Squall line is» 100 km long and we've got 50-60 km of the line in the lobe. Max Zh's typically > 50 dBZ.
17:48 Lots of good phase shift, line of Zdr > 2 dB at leading line.
17:49 Squall line filling in³ 150 km long.
18:00 Stopped and re-synched with TOGA to within 10 sec.
18:13:30 Vertical pointing scan. No Zdr bias. Preliminary analysis suggests mean Zdr = 0.00 dB, median Zdr = 0.00, Std. Dev. Zdr = 0.18 dB.
18:15 RHI's centered on 22° NNE.
18:17 RHI's centered on 128° SE.
18:20 Back to meso dd e near (trmm1.scn).
18:29 Stopped meso dd e loop.
18:30 Rain gauge 2,3,4 scan. Heavy rain. Bulls eye hit. Inner RHI's 339° . Outer RHI's over gauge #2.
18:34 Shift inner RHI's to 342° .
18:41 Shift inner RHI's to 339° . Nice RHI! Tops 15 - 17 km.
18:45 Shifted inner RHI's to 323° to cover TOGA.
18:55 Gauge #4 getting heavy rain.
19:00 Shifted RHI's to 327° over gauge #4.
19:08 Rain over TOGA. Still in gauge 2,3,4. Shifted RHI's back to 323° over TOGA.
19:20 Talked to TOGA. They had heavy rain, strong outflow with strong winds and 40-50 flashes min-1 off of flat plate.
19:22 Stopped Gauge 2,3,4 loop; Started 2-tilt 360° .
19:29 Stopped 2-tilt 360° .
19:30 Synch with TOGA. Started "hi-res" 90° dual pol/dual-Doppler sector over profiler with RHI's. Everything centered on 22° . Covering echo. TOGA is scanning. EDITOR NOTE: this "hi-res" scan merely refers to azimuthal and elevational beam spacing. The sector is completed in shorter time but still only updates every 10 minutes. Later in the experiment when comms. with TOGA improved, the hi-res scan was improved to provide 2 DD sector updates every 10 minutes. (See 26 January for implementation of improved hi-res DD scans).
20:16 Running loop survey, 7-tilt angle. RHI centered at 240° AZ. There a line of cells 80 km to the west with 50 dBZ.
20:25 Interrupt loop survey.
20:26 RHI's over Abracos for Earle Williams (centered 323° ).
20:31 Back in loop survey, rhi. RHI centered 250° .
20:38 RHI centered at 250° .
20:49 Line of cell 80 km to west. Have tops of» 14 km. RHI centered @ 270° AZ. Unfortunately, these cells are moving to the west.
20:58 RHI centered @ 270° .
21:08 RHI centered @ 275° . Strong cell to west are subsiding. Entire radar scan area is clearing.
21:18 RHI centered @ 275° .
21:28 Still in 7-tilt survey loop mode. RHI centered @ 180° .
21:38 RHI centered @ 180° . Fairly strong cell @ 180° AZ 110 km. 40° + of phase shift. Velocity sig. at 1.1° and 2.5° show clock wise circulation. 50-55 dBZ max.
21:49 RHI centered at 180° . @ 184° AZ has a pixel or two of 60 dBZ! - 135 km range though and 2.4 to 4.8 km AGL.
22:01 RHI centered @ 180° AZ 50° + of phase shift through storm complex.
22:09 RHI centered @ 185° . Continuing 7-tilt survey loop.
22:32 3-body scattering signature @ 189° AZ in RHI. Negative Zdr in back of core with very high LDR (>-10 dB). But LDR could be due to low SNR.
22:40 RHI centered @ 185° AZ. Continued 3-body scattering feature??
22:50 RHI centered @ 190° AZ.
23:00 RHI centered @ 190° AZ.
23:10 Running loop survey2. One 5-tilt angle survey scan in 5 minutes.
23:26 Running loop survey2 with 2 RHI centered @ 260° to look at some stratiform. Start RHI.
23:36 Running loop survey RHI 1. RHI centered at 240° AZ.
23:42 Begin RHI - another nice well defined BB. Seeing some high Zdr at cloud top @ 239° AZ @ about 30 km. Very consistent feature Zdr=3 dB. Signature look real (i.e., low LDR and high r hv contiguous with the high Zdr). Probably aligned ice crystals. Cloud tops at 7.4 km BB at 4.2 km AGL.
23:52 Begin RHI. Continued high Zdr at cloud top.
January 21, 1999
00:05 RHI at
00:13 Continued high Zdr at cloud top in RHI.
00:43 Begin RHI. Continue 7-tilt survey with RHI centered at 240° .
00:49 Running loop survey2 (no RHI).
03:14 Running surveyrhi2.
03:21 RHI centered @240° through a weak BB type cell. Zh < 37 dBZ but quite positive Zdr in ice phase.
03:31 RHI centered @ 27° .
03:37 Running loop survey2 (no RHI).
10:15 Nice bird ring in Ji-Paraná greater metropolitan area. Otherwise, yet another wasted, sleep deprived night.
12:20 There is a grazing TRMM overpass @ 1355 today. It will graze N-E region. No PR data.
13:20 No luck in contacting TOGA via cell phone.
13:56 Overpass is a bust. SVR CLR. No echoes.
16:23 Weak showers (< 20 dBZ) with a couple of moderate cells (£ 40 dBZ) popping up slowly over elevated terrain primarily to NNE, E, and W.
16:44 Weak-moderate cells more widespread now.
16:50 Re-synched Survey2 to TOGA. A few of these popcorn showers are in the far reaches of the eastern lobe. Almost all cells > 60 km in range.
17:00 Stopped survey2 and started loop survey1 (7-tilt surveillance scan up to 9° ) with RHI's centered on 80° AZ (small cell to ENE) within 40 km. Cell generally restricted to below 6-7 km. Not topping cells within 40 km. Should consider going to sector. Will wait to see what develops.
17:09 Shifting RHI's to 73° to interrogate intense isolated cell about 130 km out. (The cell) died.
17:16 Started flat plate for cells within 40 km. Warm rain cells within flat plate range. Some cells with 35 dBZ tops to 6 km within 40.
17:22 Shifted RHI's back to 85° to interrogate cells within 40 km for flat plate studies. Tops to 7 km. 30 dBZ tops to 4.8 km. Narrow Zdr > 2 dB up to 5-6 km. These are RHI's of primarily warm rainers. Didn't see any lightning (on flat plate). Nice null case with flat plate?
17:36 Zdr > 3 dB in cores to ENE @ about 30 km. 10° phase shift.
17:38 RHI: tops 7.5 - 8 km, 35-40 dBZ up to 6 km. 86° AZ: convection looking more vigorous, Zh > 50-55 dBZ with WER. Popcorn clouds of 0-5 dBZ everywhere.
17:47 Shifted RHI's to 80° . 40 dBZ up to 5-7 km.
17:59 tops to 12 km, 30 dBZ up to 6-7 km.
18:06 Rotated RHI's to 85° AZ center. Isolated cells nearby: > 50 dBZ at 2-4 km AGL, Zdr > 2 - 3 dB and some phase shift.
18:16 Shifted RHI's to look at cell to NE (46° ) at R=60 km. 30 dBZ up to 9-10 km. 35-40 dBZ up to 8 km. tops 11-12 km.
18:20 Re-synched loop survey/rhi to TOGA time. Thinking we may want to do meso dd e far. Stuff to NE seems to be anchored to elevated terrain (which also happens to be jungle).
18:26 30 dBZ still up to 7-8 km to NE (45-48° ) at R=60 km.
18:28 Stopped antenna
18:30 Started loop meso far dd e. Focusing on cells anchored to terrain in middle of E. lobe. 9° was not topping before. This should top with 16° elevation angle. RHI's centered to NE (44° AZ). Tops 13-14 km. Couldn't reach TOGA with cell phone. Will assume we're synched "on the tens." Tops of cells are being sheared off in NE flow aloft. Big drops. Zdr > 3 dB (off scale). Need to have Jon Lutz fix this. Some phase shift: 40° of phase shift over 8 km or so (Kdp » 2.5° km-1).
18:53 One cell bustin' a move at range of 80 km. 30 dBZ up to 16 km @ AZ 34.5° . Tops around 18 km. Shifted RHI's: 32° - 42° AZ. Nice RHI's.
19:00 Re-synched to TOGA. Could not reach them to switch to sectors. OK though. We should be synched. 60° + phase shift along AZ of 30° . Heavy rain. Topping everything nicely. Very nice RHI's. Getting forward and rear anvil. Stuff is just bubbling over higher terrain in jungle. Each cell rapidly goes through lifecycle. By the time one dies, another is up to 16 km. Some "new" moderate-intense convection at far eastern edge of radar coverage R > 120 km.
19:16 High tops to NE: 15-15.5 km, 30-40 dBZ often below 6 km but several cells have 35 dBZ poking up to 8 km. Zdr in convection looked good. Zdr shows hard boundary in convection at melt/freeze level Zdr > 1 dB above freezing level and < 1 dB below. Didn't see +Zdr aloft as in stratiform. Electric fields affecting fall mode or just irregular ice due to riming, aggregation and splintering ? LDR looks good too.
19:20 Synched to within 20 sec.
19:30 Re-synch by restarting meso dd far east (trmm6.scn file).
19:32 Cell building closer to radar R» 38 km in DD lobe east. System is slowly moving toward west as seen in loop. Suggests no longer tied to terrain and is sustaining itself with cold pool. We're not at good angle to see low level convergence. 50 km long forward anvil with wind coming out of NE toward us. Rotated RHI's to 22° .
20:10 Running RHI meso. Change elevation max. angle to 17° from 34° and had to change timing for 10 minute loop.
20:20 Sync. meso dd scan. RHI centered @ about 14° AZ. Again positive Zdr's in ice phase. RHI sector centered at 90° AZ. Intense core at about 100 km.
20:48 RHI back to other cell centered @ 10° AZ.
21:00 Cell to north has dissipated - not much left to it.
21:19 Abandon meso dd e scans. Now using high res 90° sector to look at storm complex to east. Both PPI and RHI centered @ 108° AZ.
21:23 Begin RHI. Cloud tops» 14 km. 30 dBZ to 9.7 km.
21:29 Now complex forming a continuous line of 40 dBZ (North to South) across entire display.
21:36 Reduced max. elev. angle on RHI scan and widened sector to maintain 10 min. loop.
21:42 RHI centered at 120° AZ.
21:50 Synching hi-res dd. North edge of cell is entering East DD lobe. 30 dBZ to 12.9 km @ 108° AZ, 72 km range.
22:04 RHI centered at 64° to look at part of line entering DD lobe e (east). Largest cell is to southern end of line outside DD lobe.
Note: RHI's continue to show +Zdr in ice phase - seem too much! Bias?? EDITOR NOTE: Vertically pointing consistently showed little or no Zdr bias. Could be oriented ice.
22:20 Synch meso dd e (far). Moved center to 90° to scan entire complex. RHI's centered at 64° AZ.
22:24 Movie loop shows outflow boundary toward radar. Cloud tops to 14.5 km. 40 dBZ to 6.4 km (AZ = 60° ). 30 dBZ to 10 km in AZ=73° .
23:02 Eastern cell is about 50 km range. Lightning observed outside.
23:10 Synched meso dd e far centered at 90° to cover entire complex.
23:16 RHI centered at 147° . Through the most intense cell that is producing most lightning. 55+ dBZ core. Lots of phase shift » 50° with Kdp » 2.5-3° km-1. > 45 dBZ for about 15 km.
23:30 Synched meso dd far loop. RHI centered at 53° .
23:40 Synched meso dd e near (trmm1.scn) since cells are close now. No RHI's. Storm complex to east is very widespread now. Most intense section is south. Good cell has moved in from the NNE into DD east lobe.
January 22, 1999
00:03 Cell in near east lobe has dissipated. Cell in far east DD lobe is 100 km away. Cell to south is most interesting but out of DD lobe
00:06 Running 2-tilt 360
00:10 Synch meso dd e scan.
00:17 Running RHI meso.
00:18 Running 2-tilt 360° .
00:20 Synch meso far dd e. Will follow the distant cell in lobe for a bit.
00:23 Aborted meso far dd e. There is a 40+ dBZ cell over profiler. Running rain gauge #1/profiler scan. Can't believe it; 45-50 dBZ just to north AND south of profiler. But the north cell did go over the rain gauges.
00:35 Cell over gauge network gone. Running meso dd e far (trmm6.scn).
00:38 Running 2-tilt 360° . Need to focus on something!
00:50 Running meso dd e far. Not that much in DD lobe.
01:00 Running 7-tilt survey loop.
01:07 RHI center @ 320° AZ. At AZ 322° , could top 17 km at 96 km range.
01:19 Running 2-tilt 360° .
01:22 Running meso dd far scan centered at 34° to track all activity in North and Northwest. Strong cell centered at ~ 305° with part of complex in dd west lobe. Weaker activity <~ 40 dBZ in far region of east dd lobe.
01:30 Synched meso dd far centered at 340° AZ. Lots of lightning from complex in northwest ~ 330° AZ. Good light show.
01:50 Continue meso dd centered at 340° . Things are dissipating everywhere.
02:04 RHI centered at 290° . Main part of cell is 120+ km range.
02:10 Synch meso dd 340° .
02:15 RHI @ 180° .
02:25 RHI @ 285° AZ center.
02:35 RHI @ 285° AZ. Things are fairly uninteresting now. RHI is blocked at low elev. angles.
02:50 Begin 7-tilt survey loop with RHI.
02:56 RHI @ 310° .
03:06 RHI @ 310° . Cloud tops @ about 10-11 km. Not a real pronounced BB like seen previous days. Widespread echo area that covers NW quadrant with dBZ less than ~42.
03:17 RHI at 328° center. Not really BB/strat. type system now.
03:43 RHI shifted to 311° this loop to cover the main stratiform region.
03:47 Most everything out there appears to be weakening, some scattered convection moving in from East but not too impressive and given trend I do not anticipate needing to switch to sectors; 7.0° topping basically everything right now, so sticking with surveys; may turn off RHI's soon but not just yet. Nice bright band (BB) in stratiform to NW, but storm moving out of unambiguous range.
03:53 RHI's to 80° this loop to cover incoming convection to East.
03:59 RHI's show incoming convection to be shallow, 5-6 km basically; appears to be popcornish in nature.
04:00 Attempts at vertically pointing. Not enough power?
04:26 RHI's switched to 30° to cover developing cell at 75 km.
04:32 RHI's show cells in E. lobe to be shallow but intense; will synch with TOGA on the 40 for DD.
04:36 Cells w/in 40 km of S-pol; turning on FCM (field change meter).
04:37 Stopped antenna.
04:40 Running loop hires far dd (trmm6.scn) on NE lobe, centered @ 50° ; RHI on cell in sweet spot @ 30° .
04:48 DD topped all except some cells w/in 20 km, shifting center to 55° , RHI to 32° .
04:55 Convection is all still pretty shallow; D-Dop continued at 0450.
04:59 Stopped; reordered loop hires far dd (trmm6.scn) to have 2-tilt 360° in center so low angle surv. not cut off when resynch; this way, less critical RHI's get the axe.
05:00 Re-synched DD and restarted loop.
05:10 Restarted, clipping left edge of main storm; will switch to meso fr dd e next loop switched order of 360° 's and RHI's in meso. loops too. RHI on 27° this loop; some convection near profiler.
05:18 Stopped; oops, a bit too early.
05:20 Re-synched running meso fr dd e. RHI @ 27° .
05:30 Meso. DD loop restarted. RHI to 20° .
05:32 Movie shows long line of very weak, shallow convection forming and running from way beyond E. lobe, through S-pol, then WSW through much of the W. lobe; some sort of boundary there; light rain @ S-pol.
05:40 Resynched, RHI @ 18° ; stuff looks like it's weakening; airport's been getting light rain it appears.
05:47 Gauge net #2 being grazed by drizzle to light rain.
05:50 RHI to 9°
05:57 Stopped during RHI's.
05:58 Running loop surface net (trmm7.scn) to cover cell over net #2. Light to moderate rain @ gauges according to particle ID; main D-Dop. cell dying out.
06:18 Stopped; running loop survey RHI1 with RHI @ 22° to focus on storm far to NE; gauges out of rain now.
06:30 RHI to 72° to focus on strat. precip. in S. portion of E. lobe.
06:38 Stopped, will run meso fr DD E. on strat. precip. next 10
06:40 Synched & running meso fr DD E with RHI @ 75° , strat. is weak and probably weakening.
06:48 Significant and Kdp aloft, above freeze level.
06:50 Resynched; D-DOP continues, RHI to 73° .
07:00 D-Dop. continues.
07:10 Resynched, RHI to 353° to focus on strat. precip. to N. (still in E. lobe); reflectivities are pretty low on everything w/in reasonable range.
07:20 Resynched; have 40 dBZ in bright band on N. storm.
07:25 Added another sweep to RHI meso scan in order to better synch. meso dd loop.
07:30 D-Dop continues, adding 1 sweep really helped synch the loop better.
07:40 Resynched, RHI to 57° to focus on E. storm again; reflectivities weakening, will switch back to surv. after this.
07:50 Running survey2 scan (trmm4.scn).
08:03 Running loop survey rhi1 while I change angles on survey 2; RHI on 275° .
08:07 Changed survey2 to following angles: 0.5, 1.1, 2.3, 3.5, 4.7, 5.9, 7.1, 8.3, 9.5, 10.7° for ~ 10 min. duration.
08:10 Synched and running survey2 scan; wanted higher elevation angles to top more of weak strat. precip, synched for D-Dop. just in case anyone cares about airflow in 20-30 dBZ echo.
09:32 Clearing up out there.
11:02 Another bird ring around Ji_Paraná this morning.
12:30 Goofing around with scan files and accidentally added a few extra sweeps to 360° by switching scan files while radar is spinning.
12:30 Restarted 10-tilt survey 2 which re-starts every ten minutes. As I see it, there are two options for survey2. I've written the two options down on the inside jacket cover in the front of the log. Switch manually as needed.
Note: There are 2 TRMM overpass at 1418z and 2359z today. 1418z: TRM/LIS: No PR descending; SE-NW half. 2359z: TRM/LIS; No PR ascending graze W-N quad.
12:53 Changed survey2 (360° ) back to 5-tilt 360° (5-min) up to 5.5° since there is not much precip. above 5.5° .
Note: If there is light rain or drizzle over the antenna, let's take every opportunity to accomplish a vertically pointing scan (brazil.scn). Run it for 2 or 3 minutes. Check H-power button (2nd from left). We are looking for H-power£ -50 dBm and ³ -90 dBm for ideal situation. Noise Power ~ -115 dBm to -118 dBm. Vertically pointing scans confirmed 0 dB bias to date.
14:20 TRMM overpass sampling ground clutter here.
15:12 Slow development day. Not much to look at.
16:30 Visibly - cumulus and TCu are building outside. A few Cb's (weak-moderate) are out there. "Isolated popcorn" convection on radar. 1. SE, 103° , R~124 km, Zhmax ~ 45 dBZ (largest multiple cells). 2. NE, 54° , R~84 km, 50 dBZ. 3. SE, 109° , R~29 km, 40-45 dBZ. Scattered weak cells N-E.
16:45 Started flat plate. Cells within 40 km.
17:05 Started 7-tilt survey up to 8.5° with RHI's centered on 90° .
17:18 Many cells developing within 40 km to east. Other collection of cells 100 - 120 km to ESE. Not topping convection within 40 km with 8.5° . 60 dBZ in RHI to East (88-89° ).
17:26 Stopped loop survey, rhi. Started far polsec (up to 17.37° ) centered on 95° (left AZ: 35° , right AZ.: 155° ). Trying to top cells within 30-40 km for flat plate to NE-SE.
17:38 Stuffed up transition to near polsec. Fixed center azimuth. Some garbage data in there (2 min).
17:38 Running near polsec (up to 37° ) centered on 95° as before. RHI's centered on 90° . Trying to top for flat plate studies. 50° phase shift to east. Some heavy rain.
17:53 Topping w/ near polsec. This complex is largely out of the DD lobe so not synching.
17:55 Rotated sector clockwise slightly (center 100° ) to cover cells developing on south side.
18:00 Shifted RHI's to 109° center.
18:01 Zhmax > 55 dBZ, Zdr > 3 dB,Ñ F dp ~ 50° , nice convergent Vr signature in updraft.
18:02 There is some development in DD lobe E. but cells 20-30 km to E-S are most vigorous within 100 km. Will stick with this can for now.
18:06 30 dBZ up to» 14 km @ 108° AZ.
18:10 Shifted RHI's to 119° .
18:15 30 dBZ consistently up to 14 km in these complexes. Very nice RHI's.
18:29 Shifted sector center back to 95° . Shifted RHI to 59° to look at cells to NE.
18:37 RHI's to AZ 56° up to 75° in elevation angle taking a looking at cell that produced audible lightning.
18:40 Stopped RHI's started 2-tilt 360° to decide what to do.
18:43 Stopped surveillance and started near polsec again centered on 95° (35° - 155° ). RHI's centered on 44° . Stopped 1847.
18:47:27 Trying vertical pointing scan looks good. Some is in the right range. Vertical point scan suggest no Zdr bias (0.0 dB).
18:50 Stopped vertical point and back to sector. Running near polsec. as before. Raining moderate to heavy at radar now. RHI's 44° center.
18:53 Shifted sector slightly to 92° center for next sector. RHI's to 44° . tops to 17 km, R=25 km, 30 dBZ to 14 km.
18:57 Still raining mod-hvy.
19:05 Contacted TOGA and asked them to run 135° sector DD lobe starting at 1910.
19:07 Stopped antenna. Run 2-tilt 360° for a minute.
19:10 Running meso dd east (135° sector) synchronized with TOGA via cell phone. Hooray! First one. They're running sectors too. Gauge #1 and profiler site with precip.
19:17 Topping most everything within 30 km.
19:19 Called TOGA. TOGA didn't get synchronized @ 1910. Should be synchronized @ 19:20. Citation is on the way! Test flight.
19:23 This dual-Doppler case is in a good spot. R=20-40 km and in the sweet spot (middle of lobe). New cells coming into lobe from east at R=60 km, AZ=65° .
19:30 Synched to within 5 sec. Topping nice with meso dd e near.
19:40 Synched within 10 sec. Meso dd east is catching complex to N-NNE @ R=40 km and a short piece of a disorganized broken line of convection (about 20 km of 80 km) which stretches south of eastern lobe.
19:50 Re-synched with TOGA. Meso dd e (NEAR). Cell at AZ 350° , R=41 km reported to have 2 lightning flashes total.
20:02 There are no less than 20 individual cells in DD e lobe within 70 km. Cells are up and down. Cells quickly dissipate and new one starts.
20:03 Radio contact with Citation!
20:07 Larger convective complex 120 km out.
20:10 Synched within 10 sec. Rain over rain gauge network #2. Must stay in DD scan for Citation.
20:15 Citation working stratiform remnants behind convective cells. Turbulence. Min. sized graupel. Approximate AZ. 355° and R = 19 km.
20:20 Resynched with TOGA.
20:24 Citation in decayed convection (338° , R~43 km). Needles, aggregates, HVPS and CPI working with precip.
20:29 Stopped antenna.
20:30 Started meso DD east (FAR) centered @ 32.5° . RHI's centered @ 350° .
20:36 TOGA having problems with timed sectors in their antenna controller. They're having to manually restart and sometimes missing synchronization by up to 1 minute.
20:40 Restart S-pol meso far dd e.
20:43 AZ: 350° , R=54.8 km: Citation in and out of moderate rain.
20:50 "synched" to tens within 10 sec.
20:54 Switched RHI's center to 358° where Citation (R=62km) is flying low level pass through moderate isolated cell at low levels (40-50 dBZ). Citation covering 2 cells in racetrack: 1) mod 30-40 dBZ cell, 2) mod-intense shallow convection with Zhmax 55 dBZ and Zdrmax of 2.5 dB, with 40° + phase shift. Nice RHI's. Larger convective complex to ENE at R~90 km at outer edge of E DD lobe.
21:09 Stopped antenna early to resynch. 21:10 Resynched.
21:13 Shifted RHI's to 320° to spiral in convection there. (R~70km)
21:17 Shifted 135° sector to 10° center to keep track of Citation and system to east RHI's 320° center.
21:20 Called TOGA and put them back in 360° surv. volumes synchronized on the tens.
21:25 Shifted RHI's to 314° .
21:30 Citation heading to airport.
21:34 Shifted sector back to 32.5° for meso dd e far.
21:36 Shifted RHI to 48° to look at cells to NE. Mostly shallow and weak-mod. intensity.
22:01 Running loop survey2. Having trouble with the real time display. Key board - top row of key do not work - Don is having a look. And there is a problem with the real time display color scale. At 22:36:17, AZ=311° , Range=65.5, elevation=7.1° , the real time display shows unmistakably positive Zdr (Don confirms) while the Zebra display show 0 Zdr. EDITOR NOTE: This was never confirmed. Unclear "how positive" display was biased or if the exact same pixels were being displayed.
22:46 Still running survey2.
23:13 Can display all variables (on real time display) now.
23:44 Running rain gauge scan loop airport. Mistake! Nothing there!
23:45 Running rain gauge scan #1,2,3: very, very light rain over #2 gauge network.
23:56 Back to survey2.
January 23, 1999
01:02 Nothing much out there - a couple of cell out at 110-130 km to the west, otherwise clear. Still running survey2.
01:25 Ran some PPI sector scans to NE - was editing 2-tilt 360
01:28 Running survey2, 10-tilt angles.
02:00 2-tilt 360° survey. Nothing out there.
03:28 *Very* clear.
04:20 Visual lightning, but no storms in range of radar; must be way out there.
06:38 Running Survey2 scan; some30-40 dBZ cells far off to SSW and SE and want to cover more of their vert. structure; no need for sectors.
09:00 Broad area of strat. precip. in W. lobe but significant blocking and low reflectivities make dual-Doppler likely not worth the trouble; may try it if reflectivities increase though.
09:09 Ah, what the hell. Stopped antenna.
09:10 Started meso far dd w (trmm6.scn). Synched at the 10 spot, RHI @ 242° .
09:14 Peak Zh in this strat. is maybe high 30's dBZ.
09:17 Topped just about everything outside 30 km; I think this is fine given marginal nature of case.
09:20 New volume, RHI to 245° .
09:30 New DD volume.
09:40 New DD volume.
09:50 New DD volume; scans timing very well, so resynching hasn't been necessary yet; RHI to 250° .
10:00 New DD volume.
10:10 New DD volume.
10:16 System appears to be weakening somewhat.
10:20 New DD volume.
10:30 New DD volume.
10:40 Resynched, new DD volume.
10:50 New DD volume.
11:00 New DD volume; storm has weakened and is moving out of the lobe; will start general surveillance after this volume.
11:09 Stopped antenna.
11:10 Started survey2. Synched on 10 for one last D-Dop. scan.
12:00 TRMM overpasses today: 13:05: PR/TMI/LIS, descending, PR graze NE 150 km RR
22:49: PR/TMI/LIS, ascending, PR NE-SW Quad. Edge of PR within about 30 km of S-pol.
13:05 TRMM overpass a bust.
NOTE: Lowest elevation angle was changed from 0.5° to 0.7° to avoid partial blocking.
13:30 Changed survey2 back to 5-tilt because it is svr. clear out there.
14:07 Running 2-tilt survey while working on scan files.
14:14 Stopped antenna. Running loop survey2.
14:40 Isolated popcorn convection developing. W-NW, > 60 km; NE-SE, >40 km. Winds out of due east at lower levels. Veering a bit a with height to out of southeast aloft. At top of profiler wind begins to again to S-SW.
16:02 Radar down for maintenance.
16:02 Running 7-tilt survey.
16:04 Convection almost all azimuths outside of 50 km. A couple of cells within 30 km to ENE-E. (60° -90° ). Tons of cumulus (0-5 dBZ) within 50 km on scope.
16:08 2 cells within 10 km to NE.
16:09 Stopped antenna. Started survey loop with RHI's to NE (center 63° ).
16:10 Running RHI's with higher elevation angles (60° ) to NE-E for close in convection. 7 km tops mostly; occasional 10 km top. R ~ 5-10 km from S-pol. Should be nice flat plate null case w/ most of mass below 5 km so far.
16:26 Stopped antenna. Running survey1 (7-tilt) with RHI's.
16:28 Widespread isolated, moderate intensity (40 dBZ) cells outside of 40 km. Several cells very close to radar (< 10 km). Shifted RHI's to NW to look at distant (R~80km) deep convection. Changed top angles of survey1 from 9° to 8.5° to have better elev. resolution for this surv. scan.
16:41 Shifted RHI's to 302° Topping 20 dBZ everywhere except within 25 km.
16:47 Changed survey2 back to 10-tilt.
16:55 Weak/isolated cell approaching gauge network #3. Will not do gauge scan. Cell too small and weak to change scans (would take too long).
16:57 Stopped survey1/rhi and started survey 2 with ten tilts which lasts ten minutes. Cells are too small to pick large RHI sector. Survey2 also gives better elev. angle resolution.
17:01 Widespread convection continues NW of dual-Doppler lobes. Also to SE of network as well.
17:02 Saw 60 dBZ to SE (120° ) about 80 km.
17:05 Some cell building into northern part of western DD lobe. Also cell entering E. lobe.
17:10 Re-synched loop survey 2 with TOGA "on the tens" just in case.
17:12 Widespread disorganized cells which are isolated and sometimes merge to form larger complexes. Cells moving from ENE to WSW today as opposed to yesterday which was from E to W.
17:29 Not topping cells < 25 km range. Topping most cells < 25 km range. Topping most cells outside 25 km except 50 km to SE. No clear targets to choose. I'm still synched. Gauge networks have had some near misses. Cells don't spend long over network if at all.
17:40 Re-synched. Also, slowed down survey2 "a hair" to 6.1° s-1 to get closer to 10 min cycle.
18:07 # of cells > 30-35 dBZ at 1.1° seem to be decreasing over radar coverage area. Activity decreasing.
18:10 Took same RHI's to SW-SSW.
18:12 Restarted loop survey 2 (10-tilt).
18:15 A line organized to extreme NW, R~ 130-150 km. Everything else is isolated and disorganized weakening around radars.
18:17 Not worrying too much about "synching." No (little) convection in lobes.
18:22 Not topping cells within 30 km.
18:23 Citation flying near line of convection 135 km to NW.
18:35 Searching for best target for Citation. Line to extreme NW. Suppressed around 100 km of radar except for isolated popcorn stuff. More widespread convection moving in from East. A line pattern is organizing, particularly to E-SE.
18:43 Stopped antenna running far polsec. 120° sectors centered on 90° AZ. RHI's centered on 80° .
19:00 Citation is about along AZ 80° to 81° .
19:03 Timing on far polsec loop is very close to ten minutes.
19:04 30 dBZ tops are very shallow (< 6 km) in broken convective line to east. Very different than yesterday. We are easily topping everything with FAR polsec...a bit overkill. Could reduce tilts? Convection is forming along cold pools to form lines.
19:15 Citation running E/W racetrack along 81° azimuth. Temp. +1° C to 5° C. Rotated RHI to 81° .
19:17 Northern edge of broken line is approaching eastern dual-Doppler lobes.
19:20 Re-synch. far-polsec so that a half-baked dual-Doppler analysis could be done on eastern lobe. Anvil is sheared eastward to ENE while 30 dBZ tops are shallow with tops to 5-6 km. Looks oceanic like (TOGA COARE comes to mind). Line is broken with individual cells. Saw 1 cell with 30 dBZ to 7 km.
19:30 Synched to within 10 sec to "tens"
19:47 58 dBZ along 77° AZ. about R=90° -95° .
19:49 Shifted RHI's to center 88° . Still working 120° sector centered on 90° . Citation is working new convective development on west-southwest end of convective complex.
19:57 Rotated PPI sector 30° counter-clockwise to a center of 60° in order to cover dual-Doppler lobes better and still focus on Citation. RHI center back to 82° .
20:00 Synched to within 30 seconds.
20:03 Moved 1 of the RHI sector to after the 2-tilt 360° so that if we need to interrupt, it won't stop 1.1° 360° sweep prematurely.
20:10 About 60° of phase shift at 82° .
20:20 Nice velocity signature with sloping updraft. Re-synched to within 30 sec. on the "tens."
20:26 Interesting appendages in precip. normal to original line. These new cells are developing along a boundary E/W which existed before from a cold pool. This E/W boundary causing appendages normal to N/S line. Boundary was evident in Vr and Zh long before convection developed.
60 dBZ reflectivity up and around 5-6 km along 80° AZ or so. Frozen drops collecting water?
20:37 63-64 dBZ! 45° AZ., 45° -70° phase shift.
20:41 tried to re-synch. Missed by a bit.
20:42 70° -80° phase shift to NE.
20:45 Short convective line is continuing to make its way into the eastern DD lobes.
20:46 Will need to re-synch. better @ 2050. Upper 50's to 60 dBZ is common in these cells to NE at about 5 to 6 km.
20:50 Re-synched. Rotated Azimuth to 45° . Need to decide if we should go to NEAR in order to top convection within 40 km.
21:00 Switched to near polsec. Center AZ. is wrong on first attempt (95° ). Next should be correct at 60° .
21:04 Beautiful tower almost over the radar.
21:07 100+D F dp @ 36° AZ at 1.1° , 140° + D F dp ! Can see negative Zdr along radial that has 140° of phase shift. 3+ dB Zdr also present.
21:18 Running airport/profiler rain gauge scan. Main part of cell not there yet.
21:23 Should be raining over 2DVD now. If 2DVD running, this will be great case.
21:30 Running near polsec.
21:36 Running airport/profiler rain gauge scan. ~45 dBZ over profiler.
21:56 Running near pol.sec. scan.
22:06 Running rain gauge2 scan. Raining over #2 network.
22:20 Running near pol sec centered at 355° AZ. Storm is widespread and to the NE centered at about 340° AZ. A few pixels of 55 dBZ left.
22:29 Velocity show rotation and there is a small WER at ~ 325° , 45 km. New cells are forming along the radial that bounds the storm complex to the west ~300° AZ. Outside looks very dark to NNE and the lightning flash rate is quite high (30-40 min-1).
22:40 Synched near pol scan. New cells are developing quickly on western flank. Newest small cells are due east.
22:49 RHI shows nice line of forming cells. TRMM overpass now.
23:02 Things falling apart now.
23:09 RHI @ 298° shows curious negative Zdr along a radial. It's a low Zh area so could be SNR problem??
23:20 Running survey 7-tilt angle.
23:28 RHI centered at 40° AZ show another good BB. Zdr positive all the way to ground. Velocities are positive. At the BB with negative velocities above and below BB. Cloud tops are also positive V. LDR, Zh, Zdr, r hv all mark BB.
23:47 RHI @ 0° . More well defined BB. Zh to 45 dBZ. LDR limit in ice phase is about -27 dB.
January 24, 1999
00:05 Very wide spread region of BB to the north.
00:07 Running rain gauges #2,3,4 scan. Light rain over #2 network Z=35-40 dBZ. Zdr = 0.5 - 1.5 dB.
00:21 Running all rain gauge scan mode. Some light rain at airport.
00:34 Survey 7-tilt with RHI. RHI's go through BB to North. BB again has a 4 layer velocity structure.
00:53 BB dissipating. No Zh BB to speak of but BB still marked well by LDR,
00:59 Running 2 loop survey with no RHI's. Things are dead.
02:40 Running 7-tilt angle survey loop with RHI. A cell is growing at 355° AZ, 104 km range. A few pixels of 50 dBZ. Cloud top @ 12.3 km. ~50° D F dp with Kdp ~ 2° km-1 average.
03:00 Running hires far dd centered at 355° to follow cell to the north.
03:15 Running RHI's through cell to the north. Cloud top ~ 10 km.
03:40 Synched high res dd scan.
03:50 No need to synch D-Dop scan as storm is basically out of lobes. Very nice isolated intense cell.
04:00 Resynched scan anyway for kicks, maybe someone will wanna do D-Dop on the anvil.
04:05 Moved PPI center to 345° to follow storm motion.
04:09 System appears to be weakening somewhat, may also smack gauge set #4 in a few; will switch to gauge scans if that happens.
04:18 Storm's petering out rapidly; mostly light rain now as it just begins to brush up against gauges.
04:29 Stopped, running loop surface rain gauge net (trmm7.scn) on decaying storm over gauge net # 4.
04:44 Almost like gauges have a force field; main cores haven't hit it yet; actually storm has become stratiform now, with strongest reflectivities farther north.
04:53 Convection is decayed considerably near gauges #4. Not worth it to scan them anymore.
04:55 Stopped, started survey2 scan (trmm4.scn). Broad region of stratiform rain to north.
05:20 Synched up loop mesofr dd e, RHI @ 5° covering portion of stratiform in N. end of E. lobe; peak Zh 25-30 dBZ mostly.
05:30 DD continues.
05:40 DD continues, RHI to 20° .
06:06 RHI to 352° .
06:20 Resynched; D-Dop continues, strat. precip. appears to be weakening; not much left in lobe; minor Zh max in northern end.
06:30 New DDop volume; RHI to 15° .
06:41 RHI to 20° .
06:49 Stopped; started survey2 @ 06:50 due to increasing marginality of case.
11:28 Woo hoo! Double bird ring in the Ji-Paraná greater metropolitan area this morning, around 10z.
Note: TOGA radar has a new desk cell phone with a higher gain antenna. Give it a try. #976-1574.
12:12 Running loop survey2.
15:30 Working with scan scheduler to develop 4 minute sector scan for TOGA radar.
15:30 A few popcorn cells to south.
15:54 moderate cells 80-120 km to south are filling in a bit as they merge. A few cells popping up 120 km to E.
16:28 Isolated convection beginning to pop all around. Closest cells 45 km to east. 0 dBZ popcorn TCu filling radar screen from 0 to 80 km range @ 1.1° tilt.
16:56 Complex of cells to E-ENE at range 40 km, E @ R~120 km, S @ R~80-120 km, NW @ R~ 60 km.
17:00 Winds are southerly at surface and more NE with height (backing). Cells are moving toward the WSW (out of ENE-NE).
17:07 The cells 30-45 km to the east are continuing to develop. Zhmax³ 50 dBZ. We are still running loop survey2 as we decide targets for Citation and ER-2.
17:11 Started flat plate with convection within 30-40 km. Not topping cells within 40 km.
17:25 RHI's from 63° - 85° to look at cells within 40 km. Most 30-40 dBZ @ heights < 5 km. A few cells popping up to 7-8 km with 30 dBZ. One tower with 30 dBZ up to 9 km.
17:28 Back to loop survey 2.
17:30 Widespread moderate cells to S - WSW outside of 40 km. Scattered cells to W-NW outside 50 km. Widespread cells to ESE-NNE both close by and at distant ranges. Convection to East beginning to develop new cells on the northern side in the Eastern DD lobe.
17:50 Started meso dd e (far) shifted to a center of 68° (Left AZ: 0.5° , Right AZ: 135.5° ). RHI centered on 99° . Synched to tens. ER-2 bow-tie point 95° @ 90 km. Rotated RHI's to 95° - 96° center. Shifted RHI's to center 102° . Cell building on south side.
18:20 Rotated RHI's to 108° .
18:38 Rotated RHI's to 137° . Rotated PPI sector to 78° center. AZ left: 10.5° and AZ right: 145.5° . RHI centered on 138° .
18:59 PMAC problems. Radar down.
19:04 Running loop mesofr dd e
19:05 Restarted loop mesofr dd e with center of 98° . Center of RHI's @ 143° .
19:13 Running RHI meso @ 217° (212° -223° ). Hunting for targets!!!
19:16 Stopping antenna. Running loop meso dd far e.
19:20 Stopped antenna. Running 5-tilt survey up to 5.5° (Survey2).
19:39 Had 55-60 dBZ up to 5.5 km AGL.
19:46 Started loop far polsec centered on 240° ; cell ~ 60 km out, peak Zh in mid 50's.
19:49 RHI this loop 239-249° . Citation flying the cell of interest.
19:52 SignificantF dp aloft (above freeze).
19:57 Storm forming a short SSW-NNE line
20:00 Synched up to TOGA on 10's with loop far polsec; RHI center to 237°
20:10 New loop synched up w/in 8 seconds. RHI to 235° .
20:19 New loop synched w/in 18-20 sec. RHI to 234° .
20:28 RHI shows 30-35 dBZ throughout depth of main core. (~15 km I believe).
20:30 Re-synched loop far polsec on the 10's. Volume has also been covering portion of cell ~ 30 km due west, not topping it though.
20:55 Running hires meso to look at developing cell @ 280° 21 km range. 50+ dBZ core.
21:00 Re-synch hires meso - didn't have correct center angle for PPI scan - now @ 280° .
21:39 Running 10 tilt angle survey. Everything has been falling apart.
22:13 Just a few isolated very small cells. Mostly clear -- continuing surveillance scans.
22:22 Running RHI through some weak BB centered at 237° AZ.
22:25 RHI's not very interesting. Reflectivities too low. Going back to survey scans.
22:52 Don brought down the transmitter for maintenance check (only for 15 sec or so).
22:14 Running two tilt 360° survey.
23:24 Antenna hung at ~ 73° elevation! Don is trying to reset.
23:27 Two-tilt 360° running OK now.
January 25, 1999
00:31 Tested .5
06:41 Running two-tilt 360° survey. Has remained clear since last entry.
06:50 Running the 7-tilt survey to look more closely at a small cell near the #4 rain gauge site. (Not much there).
07:10 Going back to 2-tilt survey. Not too much happening. A cell to east at about 141 km (73° AZ) has 35-45 dBZ reflectivity values and seems to be building.
07:17 Running survey rhi1 loop to do an RHI on the cell (and practice using control interface). Centered RHI on 72° .
07:30 Going back to 2-tilt survey.
07:55 Watching the cell to the east; it may be moving into the DD E lobe.
08:16 Running trmm3 (polsec) focusing on the cell to the east.
09:30 The cell to the east just seems to be hanging there. Portions are moving in the edge of the DD E. lobe but they are weak and broken.
09:57 Running the rain gauge loop. Some light showers occurring over gauge network #2 (25-35dBZ).
10:24 Still running rain gauge, while the reflectivities over gauge net #2 have weakened (< 20 dBZ), it looks like a cell may pass over the #4 network.
10:30 Small cell is at the edge of gauge net #4 (35-40 dBZ).
10:40 Looks like some light rain maybe reaching the ground at site #4, so continuing to run rain gauge loop.
10:58 Edge of cell is still over #4 network. Looks like approx. 20 dBZ reflectivities to the ground.
11:21 The small cell that was sitting over the #4 network has moved off and is weakening.
11:30 Stopping the rain gauge loop. Starting the 2-tilt 360° survey.
12:03 Stopped; running survey2 scan to 10.7° , weak stratiform extending off radar screen to north.
Note: Apparently work has begun on a new desk phone @ S-pol; should be installed by Wed. or so.
13:54 Little out there: part of strat. region to north, some tufts of 10-15 dBZ far to south and west.
15:29 Little cell developing about 120 km out to south; high-tilt 360° 's continue.
15:47 S. cell still developing but distance makes it not best case for sectors; topping it @ low angle.
15:50 Stopped; running loop survey rhi1 (trmm4.scn) with RHI @201° to cover S. cell; Peak Zh in mid 50's @ low levels.
16:00 RHI shows cells to be shallow, mostly to 5-6 km; one cell in storm has 30 dBZ to 8 km or so. Will stick with survey and RHI for now; developing cells far to west.
16:20 S. storm has 30-35 dBZ up to 14 km or so.
16:31 Stopped; Running loop far polsec on S. storm @ 203° , RHI on strongest part @ 207° .
16:39 West storm not so bad either, but is directly behind that major block.
16:42 RHI this loop to 201° to cover newer portion of storm.
16:47 Peak Zh still over 50 dBZ; vertical structure fairly vigorous but not that intense, about same as before; tops to 13 km.
16:50 Individual cells in storm are elongated horizontally, almost like mini-lines.
17:03 RHI to 191° ; forgot to mention that I switched it last loop to about 195° and 198° the loop before that.
17:11 RHI to 193°
17:19 Complex has grown to point that S. portion extends off radar screen. Overall cells are much more spread out, with lots of stratiform filling the spaces between; cells look slightly weaker too.
17:37 Talked to TOGA; they will test out their hi-res dual-dop scan on their end later today if possible; they still have the sector synch problem but it is intermittent and can be worked around. Maybe when things are less busy we can do a full test w/ both radars doing the scans together.
17:42 RHI this loop to 273° to check out W. storms. S. storm weaker and moving off screen, so may switch to the W. storm soon.
17:46 W. stuff not so bad even with blockage; about 50 dBZ or so peak; good phase shift.
17:49 Started loop hi-res far DD on W. storm @275° ; In lobe, at least eastern portion is, so should have synched for DD (as it was I was w/in 20-30 sec); will synch on 10's next loop.
18:00 Scan came w/in a few seconds of the 10 so no need to resynch
18:07 Talked to TOGA again; will try combined scanning on W. storm @ 1810, with fallback @ 1820 if TOGA can't synch up in time. Plan to try this for ~ 1/2 hour and see how things go.
18:10 Had a phone call and missed synch time; I suspect that we were close enough based on last loop time.
18:20 Synched w/in a couple of seconds.
18:30 Resynched; these scans will cut out a portion of the 1.1° 360° scan when we resynch.
18:40 Stopped; running survey2 scan.
18:47 Talked to TOGA. Scan timed out fine. However, scan was designed so that there is no data beyond 70 km! TOGA going to work on this presently and will call when they come up with a final solution.
18:52 Running loop survey/rhi1 with RHI on small cell to SE @ 100 km or so, RHI on 121° , not much else beyond stratiform out there.
19:01 RHI shows cell to be shallow.
19:05 RHI to 124°
19:14 RHI to 128°
19:17 BTW, ER-2 took off about 1800Z; Citation due for 20:00 take off.
19:19 8.5° tops everything but close-in anvil.
19:26 RHI to 142° to cover developing cell @ 90 km.
19:35 RHI to 237° to cover weak cell > 120 km SW; Things really have shut down. The cells have < 45 dBZ max, are very widely scattered, small, and shallow.
19:42 RHI reveals yet another shallow cell.
19:45 RHI to 97° to cover cell just coming into range of S-POL.
19:54 RHI back to storm @ 237° ; biggest thing in range now; ER-2 will be on station shortly.
19:57 ER-2 to bow-tie cell @ 97° , 140 km or thereabouts; RHI will be switched to that next loop.
20:03 ER-2 about 1 minute out; running loop hires far dd for better time resolution on storm.
20:04 Forgot to change center of volume now re-started on right location.
20:18 Storms being topped very easily; created hires very far scan in trmm6.scn. For very far scanning on marginal aircraft places; basically has 1/2 the angles as hiresfar dd; still running hires far; very marginal ER-2 case - not a lot out there. ER-2 running bowtie on cell of interest.
20:31 Stopped; running loop far polsec on 140° to support ER-2 ops on linear flight pattern over weak distant convection/stratiform/anvil; Again, very marginal case.
20:36 RHI @ 160° reveals weak, shallow convection.
20:42 S-pol cell phone down for re-charging. ER-2 switching to line pattern over far south convection.
20:46 ER-2 established on line pattern.
20:49 RHI to 153° to cover northern end of line of convection. Running SW-NE 120-150 km out; previously it was on an isolated cell in the vicinity of, but separate from, this line. Case continues to be very marginal from the radar perspective, mainly due to range, shallowness, and it extending off the scope.
21:01 RHI to 154°
21:06 Citation on station, will punch clouds around TOGA before TRMM overpass.
21:11 RHI to 155° .
21:18 RHI to 159° ; BTW, vertical pointing scans (brazil.scn) when light-moderate rain occurs at S-Pol is highly recommended by the data quality staff. We do this to calibrate Zdr; don't do this when planes are flying or in heavy rain; only one 2-minute scan cycle is needed.
21:26 Action item: Print out more copies of height vs. slant range for aircraft folks using ZEBRA.
21:27 Convection remains weak, shallow, and distant, RHI to 163° .
21:31 RHI to 164°
21:40 Changed scan a bit; now only go up to 11.8° and added a couple more deg's width to RHI's to time it out right. PPI sector centered to 150° to account for motion. Storm has gotten a bit stronger. Will continue PPI sectors on S. storm w/ 360° low-tilt surveillance during TRMM overpass; ER-2 has left to start TRMM line.
21:48 Changed mind, will do high tilt 360° 's during overpass.
21:54 Stopped; started 360° survey2 (to 10.7° ) to prove there is nothing under the satellite.
22:01 Citation doing intercomparisons with tether sonde.
22:06 Significant portion of S. line extends beyond range of radar.
22:09 Seen a spike in Zh right about 252° last couple of scans at a high elev. angles; not sure if there's a source @ that direction or if there's a radar problem.
22:14 Doing PPI sectors up to 12° on S. storm @ 170° , RHI's to 170° (added a few angles to time right). Both ER-2 Citation headed to storm.
22:19 RHI reveals 30-40 dBZ through-out much of storm depth; tops ~ 16-17 km AGL.
22:22 RHI's to 175° next loop. 30 dBZ to 13.5 km or so.
22:25 Aircraft report visual obs. frequent lightning. This is an excellent case except for the range and lack of dual-Doppler; ER-2 running bowtie pattern, Citation en-route.
22:31 Seeing Zh spike same location but at low elev. now RHI to 182° .
22:33 Recent RHI shows 55° F dp shift through cell.
22:35 New cell just w/in 60 km @ 160° (also being scanned by S-pol); Citation is working this cell.
22:41 RHI to 184° .
22:48 Main core outside of 120 km from S-POL; RHI to 185° ; Citation on way home.
22:59 ER-2 continues to report frequent lighting in storm.
23:01 RHI to 189° ; Citation largely unsuccessful in penetrating any significant convection today; ER-2 passes very successful, however.
23:06 ER-2 still reports frequent lightning; last sector did not top near cell (still like 15 dBZ).
23:09 Beautiful anvil extending far north (over 60 km) of storm; RHI's still show strong Zh and vertical development; RHI to 191° ; much of 30 dBZ contour extends beyond range of radar, main core @ 130 km, 190° AZ.
23:13 SignificantF dp shift in anvil.
23:14 Stopped; restarted far polsec @ 190° with old elevation angles and RHI configs.; RHI to 191° ; want to top nearer storm too. ER-2 off station.
23:21 RHI to 195° .
23:24 RHI to 171° to check on near storm.
23:35 Cell to south @ 180° , 60 km has 55 dBZ max (about 1 pixel) and has 30 dBZ to about 8 km. Cloud top to 13 km.
23:38 RHI centered @ 177° . Another cell developing due east of the first small cell @ 180° , 60 km. Cells are growing underneath the anvil of the previous storm to far south.
23:54 Another small cell has developed to the NE (135° , 51 km) of last newest cell.
23:58 RHI @ 150° to look at new developing cell. Cloud top: 11 km, 40 dBZ to 9.5 km AGL; cells have developed very rapidly.
January 26, 1999
00:04 Cloud top 13.5 km; 40 dBZ to 8.5 km
00:07 RHI still @ 150
00:11 Started flat plate.
00:14 The 3 cells to SE @ 150° are merging to form a SW-NE line. RHI @ 00:12 152° AZ has 35 to 12 km; cloud top 15 km. Very impressive vertical development. Spot of 60 dBZ.
00:19 Cloud top to 17.4 km! More 60 dBZ! RHI at 152° is incredible! Has BWER (i.e., supercell-like). +Zdr to 7.2 km.
00:26 RHI continue to be very impressive! 60 dBZ @ 6.8 km.
00:33 Still some spots of 60 dBZ.
00:36 Not topping with far polsec anymore. From higher elevation angles appears as one cell now.
00:40 Max. reflectivities have gone down cloud top ~ 16 km.
00:42 Running near polsec.
00:48 Begin RHI at 146° . Still a pixel or two of 60 dBZ. Kdp ~ 5° km-1 at 149° RHI. Show large area of 60 dBZ at 4.2 km. Intensifying again.
00:53 Very sharp gradient on east side of complex. Looks like a reflectivity notch marking inflow region.
00:58 Begin RHI centered at 138° to look at inflow region.
01:03 Storm is now within 20 km.
01:08 RHI @ 147° .
01:19 RHI at ~ 148° increased elevation to 45° to top storm.
01:22 Running 2-tilt 360° .
01:24 Running new near pol sec. with elevation angles to 45° . Front edge of storm is only 7 km away. Running RHI centered at 180° .
01:36 Changing near pol sector to try and scan entire storm. Elevation on PPI to 49° . RHI to 60° elevation angle.
01:43 RHI @ 216° to 60° elevation.
01:48 Lightning is almost constant outside. There is another good cell with 50 dBZ in SE quadrant @ 20 km.
01:54 RHI centered at 221° .
01:57 PPI now centered @ 230° . Still a lot of 50+ dBZ echo but storm intensity/max reflectivities have reduced. Storm came to within 5-7 km of S-Pol but no rain has fallen here.
02:06 Cell has moved into DD west lobe. Will synch with TOGA with 135° dd meso scan near.
02:10 Called TOGA and we are now running meso dd w near. Max Z ~ 58 dBZ.
02:22 Quite a bit of 55 dBZ @ 4 km AGL. Too bad there is so much blockage in west lobe. Cell in SE is beginning to move into East DD lobe. Cloud tops still at 16+ km.
02:32 55-59 dBZ peak values remain in cell. Core is due east 33 km.
02:40 Synched meso dd west scan. Other small cells are/have been popping up in the SE quadrant.
02:50 Talk with TOGA. Will run high-res dd scan (two 4-minute PPI volumes). Storm appears to be intensifying. Storm moving NW away from main blocking area.
03:00 Running high res near dd scan and should be synched with TOGA.
03:07 RHI centered at 290° . Show nice updraft notch/overhang. Rain at radar now.
03:10 Storm is weakening. Storm tops ~ 15 km.
03:18 RHI centered @ 277° .
03:20 Running high res far dd in west lobe.
03:40 Synched high res dd scan.
04:10 Storm is continuing to die out. Still doing high res dd scan.
04:20 PPI centered @ 330° .
04:28 PPI centered @ 310° .
04:40 High res dd scan is still synched.
04:50 PPI centered @ 290° .
05:10 Switch from hi res dd scan to trmm4 survey with RHI to check out cell to the east @ approximately 100 km.
05:30 Stopped the high res far dd in the west lobe and shifted to a high res dd in the east lobe. Tried to call TOGA to inform them but the phone batteries were dead. From the survey done at 0310, cloud tops are at 15.1 km, 30-40 dBZ height approximately 9.3 km, approximately 90 km NE of radar. PPI centered @ 60° .
07:10 Centering the high res dd @ 30° . There's not much movement in these cells. But nothing is occurring elsewhere so we will continue the high res dd scan.
07:20 Reset hires far dd loop scan to coincide with 10 minute hash marks. Nominal azimuth angle 30° . Cell is still at NE @ 30° /100 km with little movement.
08:00 Reset hires far dd loop to 15° nominal azimuth angle. Cell is NE @ 15° /100 km with little westerly movement. 30-40 dBZ.
08:20 Running trmm2.scn, rain gauge loop. Cell is possibly moving over rain gauge network #4. 40 dBZ maximum @ 330° azimuth/120 km range.
09:00 Running 2-tilt 360° . Not much activity, cells at R > 120 km.
10:00 Running 2-tilt 360° . No activity (except for the birds at 0° /30 km).
12:42 Woo Hoo! New phone at S-pol. Tested out comm. with TOGA, we can call them and they can call us; fairly clear.
13:48 SVR CLEAR out there, maybe a couple of weak blotches here and there; 2-tilt 360's continue.
14:16 Weak cell popping up in W lobe @ 230° , 70 km; Running loop survey rhi1 with RHI set at 230° to see if she's worth considering.
14:20 PPI shows top to 6-7 km; not too special yet.
14:26 RHI confirms shallowness of cell.
14:32 Stopped, running survey2 scan option with 5-tilt angles to 5.5° .
14:57 Continue survey2; widely scattered, very weak, shallow popcorn convection is all.
15:08 S-Pol down for routine maintenance; should take an hour or so.
17:04 S-Pol back on-line now. Scattered isolated cells to N & E. Running 400 sec survey scan to 8.5° right now; will switch to more normal scan once things are settled.
17:07 Stopped; Running loop survey/rhi1 with RHI at 77° to cover cell @ 50 km, Peak Zh ~ 45 dBZ; it is just inside dual-Dop lobe; good areal coverage with echo right now.
17:15 RHI shows cell to be shallow; < 8 km or so with little phase shift.
17:25 Will start D-Dop with TOGA at 1730 on east storm (82° ); they will do 150° rapid update 4 min's.
17:30 Scanning started centered @ 82° . Rapid update hi res far dd (trmm6.scn); synched to 1730; 40 km from S-pol is leading edge.
17:37 Both volumes topped storm.
17:40 New loop started within a few seconds of the 10-spot.
17:48 Stopped, topped both volumes.
17:50 Interrupted 1.1° scan to res-synch on 10-spot.
17:51 Main core about 45 km out.
17:54 Barely topped storm last volume.
17:55 Have 55 dBZ at mid-levels; portion of storm extends out of lobe.
17:58 Not quite topping some portions of storm.
18:00 Synched up fine without clipping scan.
18:03 OK, main core topped OK, but anvil to north of core not perfectly topped (pretty close). Not so critical so will remain with this scan strategy; unfortunately portion of core extends out of lobe.
18:10 Not quite topped (close) last volume. Storm moving out of lobe. Started loop surveyrhi1 with RHI @ 90° to continue looking at east storm; Huge squall line crossing into range from NE; provided it hangs together, it will be within E lobe in 1/2 - 1 hour.
18:25 Oh man this squall line's gonna be a monster.
18:31 Stopped 1830; started loop meso fr dd e, but scan does not cover all of squall line; will rotate scan a bit (30° clockwise); no need to synch yet as not much in lobes; RHI to 69° to cover small cell in lobe.
18:42 Respectable phase shift in storm.
18:54 Been trying to raise TOGA - No luck on desk/cell phones.
19:00 Some leading cells moving in/forming up in east lobe; still no luck with TOGA; will start synch on 10's at 1910; MCS still looks pretty good; RHI to 50° this loop (If we get to it before synch).
19:10 Forgot about synch but got within 20 sec. RHI to 60° azimuth.
19:20 Resynched on 10-spot, RHI to 55° azimuth; still no luck with TOGA, as well as a number of other cell phones, although we can call cell phones here and land lines in JP; wonder if there are cell network problems.
19:30 Synched up new scan loop. This is really a nice case, with intense cells leading and good stratiform following large portions of leading cells in E. lobe.
19:38 RHI shows nice intense cores, Lots ofF dp shift high Zh, Zdr; Good leading line conv.; good bright band in stratiform; leading convection almost cross-shaped now.
19:40 New loop synched on own to within a few seconds; RHI to 55° .
19:48 Finally got a hold of TOGA; they have been running volumes synched on 10's; phone problem apparently was due to them being on the line.
19:50 Synched up on own to within a few sec. RHI to 50° to cover most intense cell; TOGA will do 135° sectors every minutes so we'll have D-Dop every 10 minutes; most of leading convection within lobe.
19:56 Rotated sector 5° to clockwise
20:00 Resynched D-Dop.
20:05 Still topping everything; most of line reformed and inside E. lobe; RHI to 45° ; transition zone very distinct with major reflectivity holes there; very large region of significant stratiform.
20:10 Synched up within 15 sec, so still OK. Will switch to higher elev. scan next loop after the sector switches; dual-Doppler covering N. end of convective line well.
20:17 Having trouble with contacting TOGA again.
20:20 Started high angle meso loop (TRMM1.SCN) We lose RHI's with this.
20:22 Started S-Pol FCM.
20:29 Talked to TOGA finally; new storm there, raining hard, will rotate left AZ. to 305° to cover new storm (outside lobes); will lose S. portion of line but it's outside lobes and TOGA will cover.
20:37 Airport about to get smacked by leading line; L. AZ = 305° , R. AZ to 80° .
20:40 Resynched; TOGA will continue 360's to keep history on S. end of line. TOGA reports audible thunder (1-2) past few minutes; FCMs running there.
20:47 Line a bit irregular; strongest cell, S. portion a bit more separated from N. portion. Strongest cell @ 30° , 40 km. Stratiform region mostly behind N. end, not south; TOGA storm may link up with N. end.
20:53 Main cell hitting airport now.
20:55 New cell about 10 km out from S-pol to NE.
21:00 Re-synched on 10-spot.
21:10 Synched up fine on own L. AZ to 300° now, R. AZ = 75° . Missing good portion of storm with this sector, significant convection building toward S-pol, linking north and south portion of line. S. line has 150° F dp shift total through line there.
21:16 This line is huge; only way to cover it would be with 360° but then we'd only get up a few tilts.
21:22 This line about to hit S-pol.
21:25 Stopped, running RHI through 135° . Beautiful, right through S. portion of line parallel to it.
21:28 Stopped, running 360° 2-tilt.
21:30 Resynched meso loop center to 37.5° ; S-Pol losing a lot of storm, particularly S. line; most of sector on stratiform region in D-Dop, covering profiler and citation, which by the way has been flying today, punching cells near TOGA and now on its way to profiler to support soundings in stratiform region over profiler.
21:37 Rain @ S-pol.
21:40 Heavy rain @ S-pol; Don't use S-pol for convective lifecycle! Use TOGA. S-pol has been supporting Citation operations and profiler and not getting adequate coverage of line beyond low-tilt surv.
21:45 Stopped, running RHI @ 137° . Phase shift in S. line is nuts, over 150° .
21:48 Stopped, running 360° 2-tilt.
21:50 Restarted DD loop; Citation doing spirals between 3 and 17 kft. DD supporting profiler spiral between 315° -90° AZ interval.
21:54 To avoid clipping 1.1° surv scan, we should delete 0.7° scan to save time (temporarily).
21:57 Nobody answering at TOGA. Was running RHI @ 150° , switched to profiler RHI @ 23° to support Citation.
22:00 Had to skip low level surveillance, will tack it on at end of D-Dop on strat. region.
22:07 RHI's on profiler, did a 1.1° 360° surv.
22:10 Resynched meso to continue to support Citation; TOGA continues 360's; In retrospect, should have done hires DD JA during profile, but I effectively did this by cutting D-Dop short for a couple of volume and doing RHI's over JA; Wanted to do RHI's on S. Line too due to largeF dp shift there.
22:21 Stopped, running 360° surv loop surveyrhi1; RHI to 190° during early portion of RHI loop; so we can cut out early and resynch with TOGA; Citation off station.
22:29 Running RHI @ 180°
22:32 Running Survey with RHI.
22:38 Running pol. sec near centered at 235° AZ. There is a line running SE to NW south of radar. High Zdr on the leading (west) edge.
22:49 Running far polsec centered at 240° AZ. There is a lot of high Zdr all along the leading edge of the line - The line is 200 km long!
23:00 Synched far pol sec.
23:04 RHI centered at 277° - small cells are developing (?) to the east. Max Zh around 50 dBZ.
23:20 Running meso dd west (far). A few pixels of 50+ dBZ, 2.5 - 3 dB Zdr's on west end. Cloud tops ~ 13 km. There are still 3+ dB Zdr on west leading edge of long western boundary. In back (to the east) of this leading edge, everything is becoming stratiform.
23:37 Movie shows storm movement to SE and all cells are weakening.
23:39 RHI at 250° . Shows the lead edge of small convection with stratiform in back (towards the radar).
23:50 Re-synching meso fr dd west scan (far)
23:54 This system is beginning to fall apart. The stratiform region behind it (to the east) increasing a little in strength and size. May concentrate scans on this area after a couple more meso far dd scans.
January 27, 1999
00:08 Running on RHI to 70
00:11 Running meso dd w far. There is very wide spread stratiform over the radar and extending south-southeast to 150 km.
00:20 Synched the meso dd west.
00:28 Doing high elevation RHI to 80° . It’s raining at the radar.
00:38 Continuing with the high elevation RHI to 80° . Good example/good resolution for BB study.
00:50 Still doing meso dd w far, with the high elevation RHI’s. BB is very well defined in all polarimetric fields.
01:00 Adjusting RHI in meso dd w to 312° there’s a line of high reflectivities along the radial to TOGA.
01:20 Shifting RHI in meso dd w to 240° .
01:35 Stopping the meso dd w scans. Starting survey rhi1 loop, with RHI centered at 280° . There is still stratiform rain in area, however things are quickly dissipating.
02:04 Stopping survey with RHI and running survey2 loop.
02:43 Spotted an interesting BB signatures to the west of S-Pol. Running an RHI scan @ Azimuth=291° to look at more closely. Reflectivities in melting layer are 40-45 dBZ, 25-30 dBZ to the ground. Zdr’s are approx. 1.5 dB in melting layer. There is a band of high Zdr’s above the melting layer at 7.4 km. This is probably (???) due to low SNR and side lobe contamination.
02:47 Restarting the survey2 loop.
04:00 Starting TRMM4.SCN, surveyrhi1 centered at 290° azimuth. Stratiform conditions @ 290° /30-120 km range. 35 dBZ max.
04:30 Starting loop TRMM4.SCN: RHI 0.7° -17° elevation; fixed angle 2, rhi centered at 290° , survey. Stratiform conditions, @290° , 60-180 km range, 35 dBZ max.
05:30 Starting trmm2.scn, rain gauge loop. Some development starting over rain gauge #4.
05:40 Starting trmm4.scn, survey2 stratiform conditions to the west > 60 km.
06:10 Starting loop: trmm4.scn 1. PPI AZ 210-330 degrees/fixed angle 4. 2. RHI el. 0.7-7.5 deg/fixed angle 2 centered at 260° . 3. 2-tilt 360° . Stratiform conditions to the west moving westerly, >60 km range @ 260° , 35 dBZ.
09:00 running survey2, trmm4.scn. isolated patches of activity, mostly in the west.
09:20 Running loop (trmm4.scn) 1. Survey, 2. RHI el. 0.7 – 9.0° centered at 332° . Isolated patches of activity with some cells moving near rain gauge network #4.
10:10 Running 2-tilt 360° . Most activity has dissipated.
12:08 Stopped, running 5-tilt surv2 to 5.5° to cover more of very weak stratiform to SE
13:20 S-Pol taken down for solar cal.
14:30 Running 2-tilt 360° now; back on-line; clear as a bell.
14:36 S-pol not doing full 360’s on 2-tilt for some reason; stopped.
14:38 Began survey 7-tilt to experiment. Looks OK.
14:45 2-tilt 360’s working fine now.
14:46 Stopped; started 5-tilt 360’s to 5.5° . Very weak cells in W. lobe not topped with 2-tilt.
15:54 Few more scattered weak cells on screen; 5-tilt 360’s continue.
16:22 Stopped; running 10-tilt 360’s to 10.7° as 5.5° not topping some weak cells to NE.
16:37 Lotta weak popcorn convection now.
17:06 Stopped; running loop surveyrhi1 through 260° to cover weak convection @ ~ 70 km.
17:16 Very weak, shallow cells in RHI; RHI to 43° this loop to cover other weak cells.
17:26 Nada muito in the NE cells; again very shallow with low peak Zh.
17:28 Stopped; Running survey 2 10-tilt to 10.7° again.
18:31 Small line forming to west, very far away (>100 km); everything’s still pretty small and popcornish.
18:40 Stopped; started loop survey RHI1 to examine cell @ 243° with RHI; 110 km away, decent F dp shift; part of this line that’s forming
18:51 New loop RHI to 38° no cover inbound shallow convection @ 90 km.
19:03 Talked to TOGA, will start D-Dop @ 1910 (TOGA may miss due to sector synch problem) on NE convection @ 70-80 km; center on 45° ; ER-2 coming on station and will work line patterns on this; 4-minute update (HI RES DD FAR); TRMM overpass @2115Z far to North (Radiometer and LIS).
19:10 Stopped 1909; D-Dop started & synched. Changing 2-tilt 360° to 1.1° and 1.1° ; This will avoid clipping portion of 1.1° sector when synching; Will have at least 1 full 1.1° scan when running loop HIRES FAR DD.
19:17 Possible skin paint on the ER-2 at a high elevation angle.
19:22 Tops look about 10 km or so AGL from PPI; topping storm very easily; now about 65 km out, west edge of this small line.
19:24 Low-levelF dp not too impressive.
19:26 Talked to TOGA; They started sectors at 1920.
19:30 Synched on own within 10 seconds. TOGA will shift sector to cover incoming storm to North. Shifted (starting 1934) sector counter-clockwise 5° to cover N. storm better too. ER-2 will shift to North possibly next leg.
19:40 Resynched; clipped 1.1° scan, but we had already done an earlier one; new developing cell along S. line.
19:46 TOGA having some problems restarting sectors; may be missing volumes.
19:50 Good synch on own;F dp getting better on S. stuff; TOGA advises back on schedule.
19:58 ER-2 switching to bowtie on center storm.
20:00 Resynched D-Dop; TOGA reports need to manually resynch; They are within 1 minute or better.
20:20 Synched up on own with 10 seconds.
20:24F dp not as good anymore.
20:26 TOGA reports 1st vol each 10 minutes synching fine; 2nd not but getting within 10 minute cycle; topping storms with both radars OK but 90° width starting to get pushed; may have to switch to 135° soon.
20:33 Citation moving toward farther north line; ER-2 to switch to N-S line to cover northern storm too.
20:40 Stopped; Started MESO FR DD EAST due to growing distance between storms; TOGA to start 360’s @ 2050; RHI to 71° .
20:48 RHI shows shallow cells, 10 km max. depth.
20:50 Synched up OK; decent phase shift in one of the northern cells.
20:56 N. storm with good phase shift outside lobes; RHI to 355° .
20:59 Some Zdr over 3 dB in cells @ 358° ; Strongest cells over 100 km to North; RHI to 358° .
21:00 Synched up fine.
21:10 RHI to 2° to support Citation passes in weak precipitation to East of main core; synched up fine.
21:20 Synched up OK on own; RHI to 0° .
21:24 TOGA remains in 360’s; everything fine on their end.
21:26 Those south storms are dead, so I rotated center of Doppler sector 25° counter-clockwise with L. AZ. @ 300° to cover storm @ 315° , 100 km.
21:30 Synched up OK; RHI to 350° .
21:35 Some small cells within 30 km to North of S-pol just barely getting topped.
21:39 RHI covering one of the near cells as well.
21:40 N. storm lacks decent phase shift now; most Zh’s below 50 dBZ now; cells are pretty marginal now; most weak and far.
21:49 Most of N. storm within D-Dop lobe now but it’s getting pretty marginal now.
21:50 Good synch on the 10’s.
21:52 Citation off station now with RHI to 357° . New cell developing @ that AZ and 60 km or less.
22:00 Forgot to change 2-tilt surv. angle back to 0.7° for MESO FAR DD LOOP. Need to do that whenever I change it for HIRES FAR DD.
22:10 Stopped; both aircraft off station; running survey2 10-tilt to 10.7° .
22:40 Interrupting the surveillance scan (10-tilt) to run rain gauge loop. There are some small cells going over #2 and #3 sites. Reflectivities of 45 dBZ. Zdr of 0.5 to 2 dB. Mainly over #2 site.
22:50 Running the rain gauge loop. Max. reflectivity of 45-50 dBZ.
23:00 Some precip. still over the rain gauge network. So running rain loop again.
23:20 Messed up a high res scan. Restarting a high res scan at approximately 2 minutes late.
23:25 Will do a 360° surv. scan 2-tilt. Probably missed one with the goof up.
23:28 Surveillance scan.
23:30 Resynched high res far dd centered RHI @ 325° . TOGA not answering phone or phone not operational. There are a couple small cells just to the south of TOGA with 40-45 dBZ reflectivity.
January 28, 1999
00:03 Still doing HIGH RES DD scan on 2 small cells just south of TOGA. There are some 40 dBZ reflectivities but not many. Right now it’s the only thing in town. Tried to call TOGA radar again. The phone seems to ring, but no answer.
00:20 These cells are breaking apart and dying. Will run one more 10-min high res scan then go to a 10-tilt survey scan.
00:31 Running 10-tilt survey, probably will go to 2-tilt after this.
00:52 Going to stay with 10-tilt survey (loop survey2). Nothing at all to look at. This is the clearest radar screen I’ve seen since being here!!
01:55 Nothing out there.
04:10 Running trmm4.scn (survey2). Restart. No observable activity (very clear night).
06:00 No observable activity.
10:00 No observable activity.
10:30 Small cell @ 15
11:56 Switch to 5-tilt survey to 5.5° at beginning of next loop.
NOTE: If desk phone at TOGA doesn’t answer, call cell phone , then try sat phone as last resort.
13:14 Talked to TOGA; they are working on sector synch problem.
NOTE: They prefer to do full volumes, so we should not try to get them to do rapid-update sectors on just anything. Emphasize aircraft ops, well-placed cells, good lifecycle/electrification cases, or otherwise very intense storms for rapid update (4-minute D-Dop); Do try to get a hold of them regardless, however.
14:56 Best we got out there right now is < 15 dBZ.
15:40 To 10-tilt survey to 10.7° next loop; lots of weak popcorn convection, especially East.
16:43 Well, there are storms, but nothing close in and most are nondescript.
17:10 Stopped, running lop survey RHI1 with RHI @ 242° to cover cells @ 70 km range.
17:19 TOGA called; suggest intercomparison study in the event that something interesting pops up in the lobes. RHI doesn’t show storm to be anything special.
17:20 Stopped; restarted survey2 to 10.7° .
18:21 A lot of scattered cells, but the best are 80+ km out and even they aren’t very notable; continue to do 360° surveillance to 10.7° .
18:26 Stopped; running RHI through storm @ 110 km, 105° ; tops look like they could be close to 10 km.
18:29 Storm is up to 10-11 km, with OKF dp and Zdr’s over 2 dB, but it’s 110-120 km away and moving south (i.e., farther away); started LOOP SURVEY RHI1 with RHI remaining @ 105° .
18:40 Stopped; started SURVEY2 again; storm is not worth more RHI’s.
19:21 Stopped; started rain gauge loop (TRMM2.SCN) with RHI on 327° to observe light to moderate rain over rain gauge network #4, mostly light based on particle ID.
19:45 Rainfall still moderate @ most gauges in #4, but increasing.
20:03 Small cell is still over #4 rain network. However, it is moving off and only trailing edge is covering gauges. Reflectivities are approx. 20-30 dBZ, light rain Zdr’s are close to zero.
20:47 Cell has completely moved off of #4 rain gauge site. Going to a 360° survey 7-tilt at the 10’s.
21:10 Running survey with RHI center at 251° to look at some possible growth to the SW.
21:20 Cloud top in this area are reaching 12-15 km. Reflectivities are 40-45 dBZ. Zdr are relatively small, 0.5 – 1.5 dB. It is toward outer edge of west lobe though at 21:30 will start the meso far dd w.
21:30 Started the meso far dd w loop with center at 252° . RHI is center at 252° .
21:38 Talked to TOGA. They are going to continue 360° volume scans. Continue to look at region with our meso far dd w loop. Cell is about 100 km to the SW and moving in a southerly direction.
22:20 Did not really developing into anything. Stopping the MESO scan and doing 2-TILT SURVEY with RHI centered at 305° . A small cell is just to the SW of TOGA site. Again this is not much. Peak Zh of about 35 dBZ.
22:22 There is more interesting development to the North East at about 140 km out. Will keep watching the development visually, if it moves into range will concentrate on that area.
22:38 Stopping RHI’s doing a 2-TILT 360° SURVEY to see where we want to concentrate.
22:40 Start 2-TILT 360° . There may be another cell getting ready to go over the #4 rain gauge network. Right now it is to NE of the site.
22:44 Cell to the NE is approaching dual-Doppler east range, but is beginning to break up.
22:45 Going to run survey with RHI at 41° to get a better look at cell to NE of S-Pol.
23:02 I will begin HIGH RES FAR DD EAST LOOP for the cell to the NE, it does have a SW’ly track on it and is moving into the Doppler lobe. I will synch this at 23:10.
23:10 Started MESO EAST DD FAR to concentrate on cell moving to the SW out of NE.
23:28 Cloud tops are about 10-12 km. Reflectivities are approximately 40-45 dBZ in the core. Zdr’s are about 1 to 1.5 dB.
23:37 The leading edge of the cell may be gaining some strength. It’s now about 90 km to the NE of S-Pol. The activity that was approaching the #4 rain gauge site has pretty much died out before hitting the site.
23:42 Talked with TOGA, we may synch up and do high res scans at 00:00. Will talk again at 23:55 to see what action to take.
23:58 TOGA called and said they were going to stay with the 360° volume scans for a while. Will call and discuss in about 15 minutes. I’m staying with MESO FAR EAST DD for now centered at 45° . Shifting the RHI to about 56° .
January 29, 1999
00:15 Cell seems to be taking a more southerly track. There are several small cells grouping together; the core measure about 45-50 dBZ. Zdr reaches 2.5 to 3 dB at some points. Maybe about 40
00:40 There is now a line of activity running N to S. The southern most point is 11° 8’, 61° 17’; the northern most point is 9° 57’, 61° 32’. The southern edge is at 83° from S-Pol and 77 km out in range. I may alternate the RHI scans between the two main cores at 65° /68 km and at 26° /112 km. MESO FAR DD E running with RHI centered at 65° . Cloud tops in this cell are approx. 13.3 km. Peak reflectivities are around 45 dBZ. Zdr are fairly low, 1 dB, with a few higher values, and F dp ~ 20-30° .
00:50 The MESO FAR DD E run will have the RHI centered at 26° to look at a cell farther to the North, in the same line. Nothing too outstanding or different from above (00:40).
00:57 TOGA radar called and wanted to run their high res Doppler scans. Will synch up at 01:00.
01:00 Started HIGH RES FAR DD centered at 47° . This covers both complexes in the DD east lobe.
01:05 Talked to TOGA. They are synched with us.
01:10 A couple of areas in the complex have 30° of phase shift, some 40-45 dBZ. The system as a whole does not seem well organized.
01:30 Still synched on the HI RES DD scan. The system as a whole is decreasing in strength.
01:58 TOGA called and are going back to full 360’s. I will change our scan mode from HIGH RES DD to MESO DD E NEAR, as the anvil is stretching back over toward TOGA site.
02:00 Wasn’t able to get ready for synching at this time. Still running highres.
02:10 Synched with MESO DD E NEAR. Probably need to adjust center.
02:30 Adjusting azimuth to 35° .
02:40 Still running MESO DD E NEAR.
02:50 System is still losing strength. No notableF dp. Peak reflectivities (at best) are near 30 dBZ.
03:40 Still running MESO DD E NEAR. Probably will soon go to 360° SURVEY 2.
04:06 Running TRMM4.SCN, SURVEY 2. Elevation angles 0.7, 1.1, 2.5, 4, 5.5° . Small isolated patches mostly in the NE > 40 km range, 20 dBZ. Larger system @ 0° azimuth, 60-120 km, 20 dBZ.
04:30 Running LOOP from TRMM4.SCN: 1. Survey, 2. RHIs centered at 330° , elev. Angles: 0.7-9° . Weak stratiform conditions over rain gauges #2, #3, #4: 15 dBZ.
04:31 Stopped transmitter because it is overheating. Being repaired.
05:01 Replaced thermostat. Running LOOP SURVEY RHI1 (see 04:30 above). Weak stratiform conditions over rain gauges #2, #3, and #4 @ 15 dBZ. Thin cloud layer @ 6 km altitude.
05:50 Running trmm2.scn, rain gauge loop. Weak stratiform conditions over gauges #2, 3, 4 @ 15 dBZ. Thin cloud layer @ 6 km altitude. There might be some activity over #2 gauge network.
06:34 Development near rain gauge network #2 intensifying 35 dBZ. Another cell moving in at 30° azimuth/120 km range @ 30 dBZ.
08:16 Cell near rain gauge network #2 dissipating @ 20 dBZ; moving away from rain gauge network #2.
08:30 Running TRMM3.SCN, LOOP FAR POLSEC: PPI centered at 0° AZ, RHI centered at 330° AZ. Small cell at 330° AZ/60 km range; larger cell at 30° AZ/120 km range.
08:50 Running TRMM1.SCN LOOP HIRES/JA DD: PPI centered at 330° AZ, RHI centered at 330° AZ. Activity developing @ 330° /20-60 km range, 30 dBZ.
09:06 Talked with TOGA to synch up on activity @ 330° /20-60 km range. We will continue on LOOP HIRES/JA DD on ten minute marks. TOGA will continue on 360° surveillance.
09:50 Running SURVEY2, TRMM4.SCN; most activity breaking up and weakening.
13:30 S-Pol down for regular maintenance.
14:08 Restarted with 5-TILT SURVEY
14:12 Restarted because antenna was ramping up angles prematurely.
14:26 Small cell in west lobe about 80 km out; will switch to 10-TILT SURVEY next loop; cell is right in blockage area.
15:02 Stopped; running LOOP SURVEY RHI1 through 265° to look at Western cell.
15:08 S-Pol dropping azimuths; stopped.
15:10 S-Pol back on line running 10-TILT SURVEY to 10.7° elevation.
15:27 Stopped, running survey with RHI through 260° .
15:37 West cell is way boring…RHI to cell @ 194° , 80 km.
15:46 Basically looking at 6-8 km tops here on this storm.
15:49 RHI to 211° to cover storm about 40 km or so out.
15:56 RHI reveals yet another shallow cell.
15:57 Switched back to SURVEY2 10-TILT
16:18 Lot of scattered convection to SW.
16:25 Well, 10.7° still basically topping everything, and none of that convection is that spectacular, so continue with 360’s.
17:11 TOGA reports sector synch problem fixed.
17:25 10.7° continues to top about everything and there still are no exceptional cells; 360’s continue.
17:53 Stopped, running quick RHI through new cell within 10 km.
17:54 Reset RHI to 45° ; cell not very vertically developed; can’t start FCM for null case as am busy copying data for Brazilians.
18:49 Yawn, popcorn! Who wants popcorn!
19:08 Switched to LOOP SURVEY/RHI with RHI @ 247° to cover cell @ 90 km.
19:18 Restarted 10-tilt surveillance cell was nothing special. Everything’s pretty small today and shallow; 10.7° continues to top it all.
19:39 Citation flying today; In what remains to be seen.
20:10 Started LOOP HIRES FAR DD, synched within 25 seconds, on 55° , to cover cell Citation will be observing at 60 km; This is pretty much a dinky cell so D-Dop not really a big deal; mainly running this scan for the rapid update.
20:17 Starting next loop, will move to a 2+ minute update scan with lower max elevation.
20:23 PMAC was acting up; reset and restarted.
20:28 Started 2-TILT 360s.
20:30 Resynched for the "hail" of it!
20:34 Going to 3 sectors plus 2 360’s next loop.
20:38 Running RHI’s through cell @ 50° , 70 km that Citation is punching.
20:40 Resynched loop; not topping cell in lobe center @ 36° , 81 km, so added more elevation scans, dropped a sector volume, added RHI’s.
20:45 Finally topped biggest cell @ 10.7° .
20:46 RHI not going through cell Citation is in, they have moved to barely reflective growing turret to SE.
20:50 Resynched within 10-15 seconds; RHI to 57° on cell Citation is penetrating.
20:59 PPI to 45° .
21:05 Rhi to 27° to cover new cell ~ 80 km out that Citation may have penetrated.
21:10 Continue to synch up well on own.
21:14 RHI to 28° ; definitely recommend keeping this 1.1° , then 0.7° 360° scan sequence for HI RES DD.
21:19 RHI back to 27° .
21:20 Resynched, was getting on 30 seconds early.
21:26 HUBBERT1.SCN; run when convection very close to radar: LDR in heavy rain.
21:28 PPI center to 25° to cover Citation on way home.
21:34 RHI to 10° to cover possible cell for Citation to penetrate on way home.
21:42 Citation penetrating said cell.
21:49 Stopped; running 5-TILT SURVEY2. Will start 10-TILT next loop.
22:37 Still running the SURVEY2 360° 10-TILT. The activity in the NE where Citation was flying earlier is dying down.
23:10 Started a MESO DD F EAST scan centered @ 22° , RHI centered at 16° . This is covering the activity in the east lobe 45 dBZ peaks at 10° 20’, 61° 46’ (82.6 km, 17° AZ from S-pol). Visually there is some electrical activity. There is another area of 40-45 dBZ at 10° 42’, 61° 30’ (78.9 km, 43° ). Zdr are not particularly high in this area. Some phase shift but very little.
23:38 Some activity over the rain gauge networks. Small cells may be hitting them.
23:40 Interrupting sector scan to run rain gauge loop. Gauge site #4 may be getting hit low elev. Sweep shows 30-35 dBZ over the site.
23:46 Basically a line of small isolated cells running from #4 to #2 site.
January 30, 1999
00:07 Going to scan over profiler site at 00:10.
00:10 Stayed with scan over rain gauge network. Surveillance scan showed nothing hitting the profiler site.
00:31 Looks like most of the precip is moving to the SW of rain gauges. There is a lot of scattered activity in DD east lobe. Will run DD NEAR E on the 10’s. There is a small cell just to the north of S-Pol (about 24 km due North) (11
00:56 Nice little gust front pushing through the S-pol site. Going to MESO DD NEAR.
01:00 Went to DD NEAR E center @24° . (TOGA was also very windy here and mod to heavy rain). Running MESO NEAR. The storm cell is too close; may use hubbert1.scn to get full event.
01:10 Went to high tilt scan to capture cell just to the northwest of S-pol (rain at site: moderate).
01:12 Front is moving fairly fast and developing a NW to SE line starting almost directly over the radar.
01:14 The main core 45-50 dBZ is now to the SE of radar (11° 18’, 61° 54’).
01:20 Shifting PPI sector to be centered at 130° . F dp is close to 70° , 15 km echo top heights.
01:40 Rain has died down at S-pol (mod-light).
02:04 Going to go back to MESO DD FAR E. Looks like there may be some formation to our north and just southeast, as well as over TOGA. Centered @ 330° with RHI 325° .
02:30 Still doing MESO DD FAR E; still rain here at site. The rain gauge sites have 25-30 dBZ over the #4 network, 20-25 dBZ over #3 network. Not much hitting #2 network. Profiler site is clear.
02:40 Talked to TOGA, they have been running their MESO NEAR for the last 3 hours. The are currently centered on the line just to their SE. The same that I am concentrating on with MESO DD FAR E. Cloud tops are at 8.4 to 10 km. If I am not covering cloud top on this scan, I will switch to MESO NEAR E.
02:45 Not covering echo tops. Going to MESO NEAR E centered at 318° .
02:50 MESO NEAR E started.
03:20 Still synched with MESO DD EAST (NEAR). Things seem to be weakening a bit in that sector. There is still a line of activity to the SE that looks more interesting, but keeping the scans in the DD lobe.
03:27 With things quieting down to the NW, this may be good time to do a vertical pointing scan while we still have mod rain here.
03:30 Running BRAZIL.SCN for vertically pointing scan.
03:36 Running 2-tilt 360° to synch back up on the 10’s.
03:40 Synched back up with MESO DD EAST (NEAR).
03:50 Centered azimuth at 298° .
04:50 Called TOGA; they are on 10 minute volume scans.
05:00 Starting TRMM3.SCN, LOOP FAR POLSEC. PPI centered at 180° ; RHI centered at 160° AZ. Squall line running SE at 160° AZ @ 35 dBZ.
05:30 Starting SURVEY LOOP2, TRMM4.SCN. Widespread activity.
05:40 Starting TRMM4.SCN, LOOP SURVEY RHI1. RHI centered at 240° AZ. Widespread activity. Cell at 240° AZ, @ 35 dBZ, 60 km range.
06:10 Running SURVEY2, TRMM4.SCN: Elevation angles: 0.7, 1.1, 2.5, 4.0, 5.5, 7.0, 10, 13, 16, 19° . Modified to try to get cloud tops that are closer to the site. Widespread activity. Squall still running along SE line, @ 160° AZ. Cell at 225° AZ.
08:00 Restart SURVEY2. Still widespread activity, but weakening.
09:00 Running TRMM4.SCN, LOOP SURVEY RHI1. RHI centered at 20° AZ. Widespread activity, weak. Small cell at 20° AZ, 90 km range, @ 30 dBZ. Reset survey2 to original 5-tilt elevation settings.
09:20 Running TRMM4.SCN, LOOP SURVEY RHI1; RHI centered at 0° AZ. Small cell at 80° AZ, 30 km range, @30 dBZ.
09:40 Running SURVEY2 (5-tilt 360° ). Most activity has dissipated.
13:01 5-tilt SURVEY2 continues on nada muito.
14:27 Really cleared out now.
15:55 Running 10-tilt to 10.7° next loop; more popcorn convection now; widely scattered.
16:28 10.7° not topping some close-in small convection to south.
16:51 Running LOOP FAR POLSEC on 210° ; RHI to 204° to focus on growing convection @ 40+ km; respectable phase shift, 20-30° , with some 3+ dB Zdr’s.
16:57 Still not topping with FAR POLSEC but tops not much more than 10 km. RHI to cover new growth @ 198° .
17:01 RHI to 194° .
17:07 Sector topped much better this time. RHI to 174° to cover new growth to east.
17:10 RHI’s show cells under 10 km, with not very significant vertical development; still, peak Zh 55 dBZ or so; RHI to 192° . Back to former cell. First time in a few days I’ve seen anything decent within 60 km range.
17:17 Little better vertical development this loop; RHI to 191° .
17:21 RHI to cover new growth @ 164° .
17:28 Rotate RHI back to older cell @ 186° .
17:31 RHI to 193° ; F dp shift less now, Zdr still > 2 dB; Having trouble contacting TOGA with desk phone.
17:37 RHI to 187° .
17:40 Stopped; started 10-tilt SURVEY2 to 10.7° as storm was 70 km + & shallow.
17:52 Light rain at S-Pol.
17:53 Stopped; started vertically pointing scan.
18:00 Restarted LOOP SURVEY2, 10-TILT.
18:04 OK, storm near TOGA now, decent phase shift, Zdr.
18:08 Lot of near convection; not likely to be topped at 10.7° ; North storm hitting TOGA now.
18:20 10.7° not quite topping TOGA storm; storm moving right down baseline.
18:35 Citation and ER-2 approaching.
18:37 Stopped; running MESO FAR DD WEST; will resynch on 10’s, middle on 315° .
18:40 Resynched on 10’s in middle of volume, RHI to 331° ; Citation to stratiform behind, ER-2 to do bowtie.
18:43 Talked to TOGA; they are in 360’s NEAR (high tilt); not a stellar dual-Doppler case but will synch up anyway
18:46 >35° F dp in cell @ 300° , 60 km+
18:49 Storms under 10 km AGL.
18:50 Synched up fine on own, RHI to 335° on Citation position.
19:00 Synched up fine, RHI to 315° to remain on Citation, but we are hitting their positions with RHI’s late.
19:11 Overpass @ 1915.
19:13 Rain @ S-Pol; Citation reports variety of ice @ 17kft; RHI to 332° @ 51 km RR to support Citation spiral down through melt level. Main storm in dissipating stage now.
19:20 Synched up well on own; RHI to cover new growth @ 273° .
19:27 PPI to 225° to cover line pattern to be started by aircraft; stratiform/moderate convection 60+ km out, RHI 270° .
19:30 Synched fine; last RHI through west convection show tops to 12 km,30 km out; PPI to 240° next loop.
19:35 Not topping W. storm; it’s right in block.
19:40 Stopped; Synched up MESO DD W (TRMM1.SCN) to top W. storm better; center @ 250° .
19:50 Synched up within 10 seconds; BTW, talked to TOGA and they remain in 360’s.
19:51 Respectable phase shift, Zdr, Zh in storm @ 245° , 30 km; aircraft remain in stratiform to SW though.
19:56 Citation reports£ 2 mm aggregates in stratiform region.
19:59 Volume also covering squall line SW of stratiform region.
20:00 Resynched; getting early with this loop.
20:06 Running RHI on 233° to support Citation measurements.
20:08 Running 2-TILT 360° .
20:10 Resynched MESO DD W LOOP; W. storm weakening.
20:16 Stopped, running RHI through 220° to support aircraft.
20:18 Running 2-TILT 360° ; 50 dBZ cell within 15 km @ 170° .
20:20 Resynched DD W within 20 seconds or so.
20:25 PPI to 187.5° next loop to cover more of this immediately south storm, which is out of D-Dop lobes.
20:43 Citation in stratiform @ 260° not covered by radar but they will do another spiral SE of there within sector. (There is a beam block ~259° -260° anyway, so not a big loss).
20:48 Aircraft working some pretty marginal targets from S-Pol’s perspective.
21:00 Running RHI through 140° to check on cell.
21:02 Running HI RES FAR DD for storm ~ 135° , 80 km. ER-2 to run bowties; no need to synch since well off lobes.
21:11 Cell is big but peak Zh andF dp have slacked off; maybe 35-40 dBZ max or so.
21:17 PPI to 125° to cover convection due east of us better.
21:23 Over 30° F dp through cells @ 105° , 40-70 km.
21:25 ER-2 moving off station, may pass over some scanned convection on way back.
22:09 Covering cell to SE right now using sector scan.
22:15 Running an RHI to look at cell to the SE. Centered @ 115° .
22:18 Running survey for 10 min scan, back to HIGH RES on the 10’s
22:20 HIGH RES FAR set as before.
22:30 Shifting HIGH RES to 25° ; there may be something building near profiler site. Also, the cell to the SE is beginning to weaken.
22:40 Running the profiler, rain gauge sector scan. Some small cells in a line are getting very close to site.
22:53 Cell that was approaching profiler is weakening and falling apart. Profiler site probably won’t get hit but will stay with this scan strategy just in case.
23:40 Going to surveillance scan, 360° 2-TILT.
January 31, 1999
00:00 Started 7-tilt 360
01:00 Volume scan 7-tilt 360° still going. Things are looking clear; nothing interesting out there.
02:30 Volume scan 7-tilt 360° ; clear out there.
04:10 Restart TRMM4.SCN, SURVEY (7-TILT 360° ); very clear.
04:22 System shutdown to fix UPC.
04:48 Started TRMM4.SCN SURVEY2 (10-TILT 360° ). UPC up; rebooting workstations.
05:20 Started TRMM4.SCN SURVEY (7-TILT 360° ) to re-synch on 10 minute marks. Very clear conditions.
07:30 Re-synch TRMM4.SCN, SURVEY on 10 minute marks. Clear conditions.
10:40 Re-synch TRMM4.SCN, SURVEY on 10 minute mark. Activity developing in the SW @ 225° AZ and in the NE @ 45° AZ both at 120 km.
11:56 Restarted with 10-TILT SURVEY2.
12:29 Some cells in east lobe but they’re all topped @ 6° .
13:25 Things have weakened/gone stratiform.
14:34 Couple new cells popping up; one near TOGA, other farther out along about the same radial; another new cell just WSW of S-POL.
14:40 10.7° topping all except SW cell.
14:42 Running LOOP SURV RHI1; RHI through SW cell @ 240° , 20 km; small cell due west @ 13 km.
14:49 Changed RHI’s in surveillance file (TRMM4.SCN); now do about half as many but do two RHI1’s per SURVEY RHI1 LOOP; sick of using 20 angles or more to get through a cell; RHI’s on 257° ; second RHI scan both storms £ 5 km AGL or thereabouts.
14:53 RHI to 334° to cover TOGA cell.
14:59 RHI to 225° ; RHI’s show shallow convection.
15:03 RHI to 217° ; cell has good F dp shift, Zdr > 2 dB but very shallow < 5 km or so.
15:13 Rhi to 332° to cover TOGA convection, line of cells way to North.
15:17 Check that; Stopped, running RAIN GAUGE LOOP, RHI to 339° , to cover light to intense rain @ rain gauge network #2.
15:38 Stopped, running 2-TILT 360° while I configure POLSEC on S. storm. Will synch up on 10’s even though storm in relatively poor D-Dop position.
15:40 Synched up and running NEAR POLSEC; N-S linear cell from ~ S-Pol out to 35 km; 40° F dp shift; Zdr’s modes of 1-2 dB; RHI’s to 193° .
15:46 Sector not quite topping nearest cell.
15:47 Northern line approaching E. lobe; TOGA storm weaker than this S. storm. Looks like N. line may link up in some way with TOGA storm.
15:49 RHI shows most of S. storm ~ 7 km or less in depth.
15:50 Synched up own within 20 secs; storm starting to cross out of lobe.
15:54 Drizzle @ S-Pol; RHI to 183° . There is kind of a N-S line running from the far north MCS S. through S-Pol and beyond; convection on this line is fairly scattered.
16:00 Resynched manually; Clipped RHI’s a bit. This is probably a good null case for electrification.
16:08 Chopped an angle off RHI permanently to make loop time better; cell ~ 35-40 km out has 10-12 km tops.
16:10 Sector synched up well on own; most of storm outside D-Dop lobe however.
16:15 Rain @ S-Pol; North MCS starting to move into D-Dop range; clear gust front coming east from S. line.
16:20 Synched up MESO FAR DD E to cover N. MCS; RHI on 180° to continue to get some data on S. line; TOGA will stay in NEAR (high tilt) 360’s.
16:27 Lot of widespread convection and we are cutting out a lot with sector, but we at least get the main MCS in the E. lobe which is probably the best course.
16:29 RHI on S. line shows tops < 10 km in general.
16:30 PPI shifted 5° counter clockwise next loop.
16:32 MCS not too well linearly organized; roughly so; has what appears to be trailing stratiform (not all on screen yet); topping things well; RHI remains on 180° ; 80-90° F dp through main cell in MCS.
16:38 RHI to 352° next loop to look through main MCS convective region.
16:40 Synched up great.
16:44 Storm not really a line anymore; mostly one giant globular convective region, which is mostly in the E. lobe, strongest portion 353° , 67 km; rest is debris/stratiform covering 335° -30° , 80 km on out.
16:47 Main core shows some growth about 5 km, but mostly it’s£ 20 dBZ above freezing level; still strong phase shifts, Zdr 1-3 dB.
16:50 Synched well, PPI 5° counter-clockwise again on next loop.
16:57 Big Zdr’s > 3 dB in main cores;F dp still strong; tops to 15 km; RHI to 342° next loop.
17:00 Good synch; another 5° counter-clockwise rotation next loop; gauge site #2 about to get smacked by main core.
17:07 This stratiform area is huge; convective cells well into E. lobe and all of stratiform still not in range. In fact, it looks like the main stratiform just coming into range.
17:10 Another loop synched up fine; PPI 10° rotated counter-clockwise next loop; RHI to cover new growth @ 11° , 30 km.
17:15 Not topping S. most cell.
17:19 Stopped; started MESO NEAR centered 0° , synched on 1720; TOGA reports 40 kt gust front @ 1700; Velocity field supports this; very nice upper-level diffluence signature at higher elevations.
17:27 Barely topped S-most cell @ 32° ; this thing’s getting so close now sectoring is becoming difficult; due to way line has reformed, only ½ of main convection is in E. lobe.
17:30 Synched on own within 10 seconds.
17:37 Another close shave with topping.
17:43 TOGA, Ji-Parana airport, Gauge network #2 all under decent rain.
17:47 Another decent top; this storm seems to have stalled out and not moved much last ½ hour.
17:49 Azimuth PPI center to 12.5° to cover convection as it shifts to our east.
17:53 5° clockwise shift of PPI next loop; keep missing the synch time; probably still within ½ minute; still rain @ S-Pol.
18:00 Managed to resynch; < 30 sec off; back to normal azimuth sector setup next loop (covering all of D-Dop east lobe); stratiform extends still all the way off the scope to the north; Can’t help but cut some echo off with this sector.
18:06 347° RHI @ 1720Z shows a really nice example of a gust front structure; 1-2 km deep with a curved leading edge.
18:09 Time lapse movie suggests system gradually growing weaker; phase shifts much smaller now.
18:20 Resynched on 10’s.
18:29 Nice phase shift/Zh in cell @ 112° , 47 km.
18:30 Stopped; running 10-tilt surv2 due to widespread nature of rain now; get a feel for what to do next.
18:43 Stopped; running LOOP FAR POLSEC centered on 90° .
18:48 112° storm not topped totally (main cores were though); RHI shows tops to 15 km.
18:52 Based on echo contour heights this SE storm should be electrified; good case to check flat plate detection range since it is the strongest thing out there; core center about 55 km.
18:54 PPI 10° clockwise rotation next loop.
18:55 RHI to 124° (actually been around this since loop first started).
19:00 BTW, sector is covering 3 main centers of convection to the east; the south is the largest and strongest, the north is the 2nd strongest, and the central is the weakest.
19:10 RHI to 135° to cover main core location.
19:12 Main core still has strongF dp, high Zh, Zdr.
19:20 Rhi to 137° .
19:23 New cell in sector @ 82° , 96 km.
19:28 Even moreF dp due to elongated nature of storm.
19:30 RHI to 140° ; that new cell bit the big one.
19:33 PPI center 10° more clockwise next loop.
19:40 Storm appears a bit weaker, but still decent phase shift; over 70 km out now; RHI to 143° next loop.
19:49 Stuff is really falling apart quickly.
19:52 Running SURVEY2 10-TILT.
20:02 10.7° tops all outside 60 km, and there’s nothing inside besides decaying stratiform.
February, 1 1999
01:00 Running SURVEY2 10-TILT, not too much happening since last entry. Both dual-Dop. Lobes have been clear and there has been nothing of interest to focus on.
02:05 Running 120
02:08 Interrupted to run 360° 2-TILT SURVEY.
02:20 Looks like some fairly widespread stratiform moving into the DD E lobe. Kind of an interesting area. Reflectivities are about 20 dBZ to the ground in some areas; tops are at about 9 km with no-enhanced reflectivity layer. There is a Zdr bright band however at around the 4 km level. A better description might be very weak stratiform? Since nothing else is going on, continuing to run the 120° POL SEC scan with RHI now centered at 44° .
02:40 Whatever organization this had, it is quickly leaving. As it tracks west into the DD lobe, it is quickly dissipating.
03:00 Going back to 10-TILT 360° survey scans.
04:40 Switched order of elevation angles for 2-tilt 360° surveillance scans (i.e., 1.1° first and 0.7° second).
05:00 120° sectors @ 105° azimuth (TRMM3.SCN).
05:40 115° azimuth on sectors.
05:48 Small cells with couple 40 dBZ pixels at 34° azimuth, 140 km range not covered by 120° sectors.
05:50 Switched to NEAR POLSEC with center azimuth at 115° . Light precipitation in blob 60 km in diameter.
06:10 Some stratiform in SE quadrant switched to TRMM4.SCN, 360° with elevation angle up to 10.7° . Maybe should do RHI’s on cell @ 140 km 35° AZ.
06:30 A couple of minutes ago, something crashed the computer next door.
06:53 MARPC clock was running 20 seconds fast so I recalibrated it with GPS time on REAL TIME RADAR. From 0630-0650, the radar might not have been working. The signal processor must be restarted and this happens every 3 or 4 or days.
07:10 Switched to 135° sector at ~ 30° center to get weak cells ~ 140 km range. They are just out of DD range.
07:30 Moved 135° sectors to 25° center. Some convection in eastern lobe.
07:38 Will be over # 2 and # 3 rain gauge networks soon.
07:40 Running RAIN GAUGE LOOP (probably not enough coverage to even be registered at the gauges).
08:06 Stopped rain gauge scans and ran a 2-TILT 360° .
08:10 Began TRMM1.SCN in eastern DD lobe 135° sector scan centered on 20° azimuth. The desk phone has not been able to be reached at TOGA radar all night.
08:31 Centered on 10° .
08:53 Radar tops around 7 km for cells to NE by ~ 100 km. No noticeable (appreciable) Zdr 0-0.5 dB typical.
09:00 Switched to TRMM3.SCN LOOP FAR POLSEC centered on 0° AZ. And with RHI’s of echoes 120° -125° AZ 130 km range.
09:14 Everything is shallow or getting topped real quickly (far away) so I just went to surveillance 360’s.
09:50 Every place is shallow. The sun is rising.
10:27 Everything’s is clearing out. Stopped RHI’s and switched to all 360’s (SURVEY2 with elevation angles up to 10.7° ).
10:31 Tried cell phone (to TOGA) but to no avail.
10:40 Brought the starting time of 360° survey closer to on the 10’s.
11:12 Some 40 dBZ echo to the south about 70 km about to 12 km AGL.
11:20 Added RHI’s to surveillance scans centered on 180° azimuth to sample stuff to the south. The Zdr is noisy and negative within it, so I don’t know what I’m looking at. The RHI’s reveal a tall skinny row of clouds with maybe 15 dBZ in mid-levels and 40dBZ at the lowest. Perhaps its some ground clutter that gets worst depending on the vertical profile of air density (refractive index). It’s a stationary pattern.
11:44 The precip ID’er guesses it’s clutter, but mostly the pixels are left blank.
11:57 Switched to 10-TILT SURVEY.
12:08 To 5-TILT SURVEILLANCE next loop. Very little on the screen.
14:37 Widespread convection, very very weak, to NW of TOGA; to 10-TILT 360’s next loop.
16:17 A bit more convection now but nothing worth sectoring; still popcornish; 10-TILT 360’s continue.
16:44 Changed loops in TRMM1.SCN; raised maximum elevation angles on RHI1 to 30° , added a 10-TILT to SURVEY, then have LOOP SURVEYRHI1 do 1 360° survey scan, then 1 set of RHI1.
16:50 Stopped, running LOOP SURVEYRHI1 with RHI on nearby cell at 68° .
17:00 Cells are relatively shallow and disorganized; RHI on another nearby cell @ 82° .
17:08 Tops to 10 km on the older convection. Main cores under 5 km or so. RHI to 86° next loop.
17:22 Stopped; running SURVEY2 10-TILT.
17:33 Stopped; running LOOP SURVEYRHI1 with RHI to 92° AZ; best storm is about 50-60 km away.
17:41 Tops on older convection to 12 km.
17:45 Stopped; running LOOP MESO FAR DD E, RHI to 98° ; center of PPI on 60° ; ER-2 to run orbits over this convection due to widespread nature.
17:57 No need for D-Dop; strongest stuff basically outside of lobes and it’s not even that strong; ER-2 on station; Citation < 15 minutes away.
18:03 This convection is only being sectored because the aircraft are flying; RHI to 50° this loop; PPI to 65° next loop.
18:10 Citation and ER-2 to concentrate on 50 km, 95° or so; older convection/anvil there; anvil goes up to about 12 km or so; RHI going to 95° instead of 50° to support aircraft; PPI to 70° next loop.
18:23 RHI to 115° this loop; cells remain weak and shallow, with little phase shift and Zdr ~ 1 dB or less. Looking at 2 short lines of convection to East, 1 dissipating @ 95° and 1 developing @ 115° ; Citation switching back and forth between these; ER-2 running bowties on the center between these.
18:32 RHI to 117° this loop.
18:37 PPI to 75° next loop.
18:43 This is pretty pathetic; Citation and ER-2 moving to cells ~ 100° , 100 km away. Peak Zh ~ 45 dBZ or so; not much to work with out there; most of these cells only have a few pixels over 40 dBZ.
18:46 RHI to 100° this loop to cover new targets.
18:55 5° counter-clockwise rotation of PPI this loop.
19:11 RHI to 104° to support Citation spiral down this loop (~ 100 km out).
19:16 That was one of the more uninspiring RHI’s I’ve seen; weak, shallow.
19:24 ER-2 to shift to short line of convection developing to NE; in E. lobe, Citation will head there too.
19:30 Synching 90° HIRES DD on this new line; TOGA to do 150° sector; been running 2-TILT 360’s past few minutes to synch up OK; center on 20° .
19:32 TOGA synched up fine too.
19:33 ER-2 finished 1st line leg; this thing is about 40 km long, maybe 5 km wide; oriented NNW to SSE; peak Zh ~ 40 dBZ or more.
19:39 Peak Zh > 50 dBZ in line center.
19:40 Re-synched; clipped part of 0.7° surveillance scan PPI to 25° next volume; Citation reaching storm now; line basically in center of lobe so this should make for a nice convective life cycle case.
19:50 Synched up fine on own; Peak Zh just about 50 dBZ; phase shift moderate at best.
19:58 Couple of cells to East of line now look better than line, which has widened and weakened.
20:00 Resynched; Clipped part of 0.7° scan Eastern most cell (strongest) in E. lobe. Citation off station now.
20:04 Peak Zh in line probably 45 dBZ; starting to link up with cells to East; TOGA reports all well on their end; synching and topping fine with both radars.
20:08 East cell now with 55 dBZ peak, 2-3 dB Zdr, OKF dp, maybe 15° -20° ; main line falling apart; still total storm more L-shaped with merger of E. cells; everything’s still within E. lobe and partially over profiler.
20:19 East cell remains relatively intense; original line continues to collapse.
20:20 Resynched; clipped part of 0.7° scan.
20:30 Synched up fine on own.
20:34 Dropped out; running RHI over profiler as ER-2 passes over.
20:35 Running 2-TILT 360’s.
20:40 Nice gust front pushing through here at S-Pol.
20:44 TOGA called and are going back to the full volume scans; they aren’t topping the cloud tops.
20:50 Going to run 10-TILT surveillance scan.
20:58 There’s a small line of activity hitting rain network sites # 2, 3, 4. Four may be getting hit the most, but still not much. 25-30 dBZ at low levels.
21:14 A line of activity is developing on a NW track from the radar at ~ 345° . Not very strong though, just small pockets of 30-35 dBZ along line. There is rain at the radar site (S-POL).
21:21 Running a vertically pointing scan. Seems like a good opportunity to do this.
22:23 Running 10-TILT 360° . The NW line talked about at 21:14 is weakening or coming apart (from little there was to begin with). A small line is intensifying just to the NW of S-POL, peak Zh of 45 dBZ at 331° , 23.6 km.
23:20 Running high tilt scan for a small cell passing over S-POL mod-heavy rain, although in the last few seconds it has died down a bit. Very short lived. Centered on 316° .
23:31 Centering the high-tilt scan at 350° . Zh = 45-50 dBZ, Zdr~1.5-2.5 dB and very little F dp as these are very small cells approaching S-POL.
23:43 Going back to 10-TILT 360° survey scan. Ran a 2-tilt scan on the 10’s so one would not be missed.
February 2, 1999
01:00 10-TILT 360
02:00 Little change in surroundings.
03:20 8-TILT 360° survey.
04:28 Finally get to witness a bright band signature. Enhanced Zh, Zdr, fluctuatingF dp (+/- 15° ), LDR just above Zdr.
04:36 Ran RHI’s just for heck of it.
04:37 I see what people mean about moreF dp shift above the freezing level than below.
04:40 Back to SURVEY 360° with 8-TILTS. Virtually no F dp shift below and 4° /10 km above or Kdp ~ 0.2° /km. Winds 15° /11 m s-1 back to 315° at 4 km AGL (9 m s-1), then easterlies above 5 km AGL (11 m s-1).
04:49 Mostly for practice, changed the fixed angle list to add on more elevation angle to the 360° survey. Now it goes to 11.2° with 9-tilts.
05:00 Added some RHI’s to loop.
05:08 Over last 2 hours, the precip. coverage has grown exponentially. In heaviest, most extensive area to the NW by 100 km, Zh < 35 dBZ.
05:20 Looks like cells are shallow. Twice the height of the brightband but only low Zh above bright band.
05:45 Had flat plate running. Might just be for practice. No visible lightning for 5 minutes.
05:47 Stopped survey and started ALL RAIN GAUGE scan. Looks like coverage extends over all of the gauge networks.
06:09 Cut off 0.7° scan and switched back to surveillance 360’s.
07:00 Widespread stratiform in E. hemisphere. Tested different elevation limits on the RHI’s and spaced them by 3° azimuth.
08:00 The antenna control PC (MARPC) hung up. So it was restarted.
08:04 I eliminated most RHI’s and added surveillance scan at 11.5° elevation. Now it’s a 10 angle surveillance volume. (0.7, 1.1, 1.8, 2.5, 4, 5.5, 7, 8.5, 10, 11.5° )
09:16 While we saw increase in coverage from 04:40-06:40, it started to fade away in similar fashion to the present. Looks like a convergence line passed over. In the movie loop you can see the centroid of activity shift from west to east across the radar scope that would put its propagation speed at around 260 km/5 hr or 14 m s-1. There’s a propagation of cells towards the imaginary line of convergence as it marched east.
10:33 Coverage reached a minimum around 10:00 and is now increasing through eastern lobe, gradually.
11:32 It has filled in a broad band stretching from N to SE part of domain. Some Zh ~ 40 dBZ 80 km to the SE. I moved the 3 RHI’s over to sample this area.
11:40 These cells are slightly more vertically developed over the moderate rain but only bulge upward about 1-2 km above the light rain cells. 0 dBZ contour is around 11 km AGL at highest point.
11:43 Zh peaks around 45 dBZ in bright band.
12:06 Running SURVEY2 10-TILT. Stratiform running across scope from NNW to SE, right through E. lobe. Unfortunately, strongest Zh’s well out of lobe, only 10-20 dBZ inside so not bothering with dual-Doppler.
12:45 Some pulsing in this stratiform band, but it is mostly quasi-static.
13:36 North portion of stratiform dissipated; S. portion still hanging around; D-Dop lobes clear mostly.
14:23 SE strat region still hanging around, about same strength as before.
14:58 It just doesn’t want to go away! Will some RHI’s through strongest portion next loop.
15:03 Stopped; 1504 running LOOP SURVEYRHI1 through 135° ; Accidentally restored wrong scans, may have to change some things in other scans to get them back the way I like them.
15:13 RHI shows distinct bright band in SE stratiform region.
15:58 Coming soon to a theater near you – "The stratiform region that would not die!"; it’s still there, about the same strength as always, about the same azimuthal region; survey with RHI’s continues; tops to 9 km, nice bright band, enhanced Zh underneath continuing to ground in some portions.
16:32 Strongest portion a bit west now; RHI to 140° next loop; some isolated popcorn convection scattered about.
16:53 RHI to 130° this loop to cover Eastern portion better; peak Zh a little bit > 30 dBZ; far eastern portion of stratiform has dissipated; movie shows gradual weakening of system during last 3 hours.
17:03 Running 10-TILT SURVEY2; no RHI’s.
17:12 Looks like light-moderate rain @ gauge network #4.
17:15 Running rain gauge loop, RHI’s to 327° to support site #4.
17:25 Main core just missing #4; will run one more loop after this.
17:35 Running 10-TILT 360s to 10.7° .
17:45 10.7° tops just about everything since it’s all shallow and 80+ km away; convection fairly widely scattered; not much organization beyond this small N-S line about 100 km to our north; nothing close enough or covering enough area to worry about dual-Doppler; movie shows trend has been toward more convection so that may change. There is some stuff in the lobes.
18:30 Started loop MESO FAR DD E for D-DOP on East lobe scattered weak convection there; RHI on N. convection @ 344° , just coming into lobe now; 3 Main centers of activity in east lobe, this northern line, and 2 storms farther east; Peak Zh in 40’s.
18:37 RHI shows tops ~ 10 km or less.
18:40 Synched up fine; RHI to storm @ 49° , 80 km.
18:46 N. storm dissipating; East storms have merged and still look viable, with > 50 dBZ in a small portion; RHI to 54° next scan.
18:53 TOGA remaining in 360’s NEAR (high tilt); some convection farther to NE; not too bad, but just outside lobe.
18:58 Tops remain 10 km or less on the main storm in the E. lobe.
19:00 Synching up fine; RHI to 56° .
19:10 Synching OK; Storms look like it’s dissipating and NE stuff not getting into the lobes too well.
19:20 Running 10-TILT SURV again.
19:24 W.lobe looking better , and more organized; Peak Zh > 50 dBZ some cells; small cells, roughly linearly organized, running from ~ 40 km north of S-POL to > 60 km out to our west.
19:30 Synched up MESO FAR DD W to cover W. lobe convection; much of it right in block; RHI to cover one unexceptional cell @ 260° (of course, they’re all unexceptional); PPI center to 270° next loop.
19:35 Topping everything fine @ 16° , TOGA in FAR volumes (lower-tilt).
19:40 Synched fine; RHI to 309° to cover most intense cell ~ 30 km to NW; it looks shallow but has > 50 dBZ in small areas.
20:40 Starting TRMM4.SCN, SURVEY2 (10-TILT 360° ).
22:30 Re-start TRMM4.SCN, SURVEY1 (10-TILT-360° ). Isolated convective cells in the S.E. @ 40 dBZ, some also in the N.E. @ 43 dBZ.
23:40 Running TRMM4.SCN, LOOP SURVEY RHI1; RHI centered at 119° AZ. Cell at 119° AZ, 60 km range, 40 dBZ (SURVEY: AZ rate set to 6.3° s-1, total loop time: 599 sec).
February 3, 1999
00:00 Running TRMM3.SCN, FAR POL SEC. PPI centered at 90
00:30 Restart TRMM3.SCN, LOOP FAR POL SEC, adjusted RHI with rate to 2.5° s-1, total loop time is 597 sec instead of 578. Cells building at 120° AZ, range 60 km, 50 dBZ, and at 70° AZ, range 120 km, 50 dBZ.
01:35 Restart TRMM3.SCN, LOOP FAR POLSEC. RHI centered at 125° AZ; PPI centered at 90° AZ. Cells at 125° AZ, 60-100 km range and 70° AZ, 120-140 km range.
01:40 Re-start TRMM3.SCN, LOOP FAR POLSEC, to coincide with 10 minute marks.
02:46 Stopped TRMM3.SCN to edit CHANDRA1.
02:50 Re-start TRMM3.SCN, LOOP FAR POL SEC, starting to rain at S-POL site activity still building in the East (30-120° ), range 20-120 km.
03:40 Re-start TRMM3.SCN, LOOP FAR POL SEC. PPI centered at 90° AZ, RHI center moved to 100° AZ. Widespread activity to the East, RHI adjusted to capture large cell at 110° AZ.
04:19 Most rain in eastern quadrant (max 40 dBZ).
04:22 Moved center AZ. of sector to 95° to get more SE precipitation.
04:27 Moved # of RHI samples to 128 from 120.
04:30 Stopped and resynched (lost couple RHI’s) to start on the ten. Plan to switch to 135° sectors (TRMM6.SCN).
04:38 Stopped and restarted at 04:40.
05:02 Centered 135° sectors on 100° azimuth. Intensity has diminished in strongest regions of precipitation from 2 hours ago.
05:11 It’s not moving too fast and nothing is staying together long enough to reach either of the lobes.
05:18 Nobody answers the phone at TOGA.
05:21 Radar tops are all below 12 km AGL.
05:31 Going to go to 360° surveillance since precipitation coverage is becoming unfocused.
05:45 Moving to 9 tilt 360° surveillance with scan rate of 5.2° s-1 to make it exactly 10 minute long. Starting on 05:50.
06:12 Cell at 150 km 45° AZ had decent Zh and Kdp but still is out of lobe. Went outside to look for lightning and saw none for ~ 4 minutes that I was out there. Radar top is around 12-13 km AGL by the 0 dBZ contour.
06:17 These times may yield good EVADs or at least VADs. I can sense convergence near the freezing left.
06:40 Moving to 6.4° s-1 and adding 3 RHI’s.
07:27 From 07:15-07:25, the radar was stopped in order to try some software. When it started again, 360° surveillance with 1.1° elevation angle were started.
07:35 Was messing around with antenna control software and missed some time. Preparing for TRMM satellite overpass.
07:45 Doing RHI’s for CHANDRA.
07:47 RHI2 (5 centered on 315° ).
07:50 5-TILT 360° ’s.
07:55:54 Started RHI2 (5 centered on 315° ) per instructions.
07:56:20 Stopped RHI2.
07:56:26 Started RHI3 (5 centered on 135° ).
07:59 Started 5-TILT 360’s.
08:18 Added some RHI’s to 9-TILT 360’s.
08:20 3 RHI’s and 10-TILT 360’s.
08:22 Bubbly convective elements sprung up NW of radar 80-100 km range. From Vr, you can tell there is vertical mixing/transport of horizontal momentum.
08:36 More bubbly cells to the east also. Looks like individual cells start along an invisible zonal line in the NE quadrant. Then they get sheared off to the NW.
10:50 100 km line approaching from east 120 km range. Max. Zh in high 40’s. Will wait until it comes into the eastern DD lobe to do sector scan since there’s still precip. across W. hemisphere.
11:10 Started 120° pol sector on squall line.
11:15 Something stopped the data ingesting.
11:19 Signal processor crashed so it had to be reset.
11:20 Data’s being recorded once again. We missed one surveillance at 1.1° however.
11:28 RHI’s shows cold pool in radial velocity.
11:36 Peak Zh near 50 dBZ.
11:40 Running RHI’s in 3 different places.
11:42 Strange screwed up number popped up on REAL TIME RADAR screen below "current val" but everything else appears fine.
11:58 A 180° sector is needed to capture cells 70 km to NNW. That’s why I fattened the 2-TILT 360° to a 4-TILT 360° .
12:20 Started LOOP MESO FAR DD E synched on 10’s; RHI to 90° ; gives a wider sector to cover east strat storm; only a portion of it in E. lobe but more will be moving in soon; center PPI on 77.5° .
12:27 PPI to 82.5° next loop; seeing significant F dp shift above the bright band.
12:30 Synched up fine; TOGA in 360’s (FAR – lower tilt); they are working fine so D-Dop synching should be OK; TOGA getting decent rainfall; NW portion of east stratiform in E. lobe now.
12:38 PPI to 87.5° next loop. This is pretty classic stratiform precipitation; well-defined bright band; RHI to 129° next loop; tops look like £ 10 km AGL.
12:40 Good synch-up.
12:46 This line the RHI will be going through is more convective in nature; Tops on it more like 1-2 km higher than rest; it is south of lobes;F dp shift not terribly exciting but with the large area that shouldn’t matter.
12:50 System synched up fine; with this developing convective line this system is looking more like a leading line/trailing stratiform MCS; only a portion of stratiform and no convection in E. lobe though.
12:56 RHI to 132° this loop; convective line to N-S oriented, about 80 km long, building in intensity although most of core remains below 5 km or so; anvil to ~ 10 km or slightly more.
12:59 Stopped during RHI’s.
13:00 Synched up MESO NEAR DD E since convective line near S-POL, within 30 km now; most of stratiform NE of convective line; north end of line just within east lobe; PPI center on 92.5° ; N. portion of stratiform remains in E. lobe.
13:09 PPI to 97.5° next loop; nice Zh hole just behind main convective line; F dp shift, Zh increasing in convective line.
13:10 Synched up OK; significant LL convection in front of convective line.
13:18F dp, Zh continue to increase along line.
13:20 Resynched manually, PPI to 102.5° ; movie shows stratiform shrinking while convective line intensifies.
13:28 PPI to 105° next loop.
13:30 Synched up fine on own.
13:39 PPI to 107.5° next loop; storm’s getting really close; full coverage getting to be difficult; clipping inevitable.
13:40 Missed synch up, but I’m sure timing was fine.
13:48 PPI to 110° next loop; will have to continue clipping north end of line, which means less and less dual-Doppler but then this was never a stellar D-Dop case anyway due to position.
13:50 Manually resynched.
13:51 Line looking a bit fuzzier, with lower Zh; but it’s still going strong.
14:00 Stopped; running vertically pointing scan; Light rain @ S-pol.
14:04 Started loop survey RHI, RHI to 171° ; line looks really messy now; may be headed toward stratiform
14:12 ~ 50° of F dp shift in RHI along line; most storm mass below 5-6 km.
14:15 Started LOOP NEAR POL SEC on 180° ; RHI to 179° ; cutting off north portion of storm but that is the least interesting part at this point.
14:25 Still seeing this +F dp shift aloft.
14:33 This thing’s headed for stratiform; looks really messy on the surveillance scan.
14:36 Stopped; running LOOP SURVEY RHI with RHI @ 182° ; storm is basically a N-S elongated glob of stratiform rain with S-POL near the center.
15:08 It’s all stratiform now; Hasn’t moved much either; started 10-tilt 360’s to 10.7° .
15:16 Up to 45 dBZ in bright band to SE; beautiful bright band signature in LDR andr hv; very distinct and I’m only running PPI’s!
15:31 Running LOOP NEAR POLSEC on 210° with RHI to 212° ; convection redeveloped just inside west lobe inside stratiform region; decent phase shift; D-Dop not synched but will synch up next loop.
15:40 Cut off RHI’s to resynch D-Dop.
15:50 Stopped; started HIRES DD JA to cover some 30 dBZ or so stratiform over JA profiler. Synched on 10’s; RHI’s to cover profiler; changed PPI AZ to 45° by mistake; will change back to 25° next loop; still covering profiler with PPI though.
15:59 Stopped, cut off RHI’s a bit.
16:00 Synched up MESO FAR DD W centered on west lobe; PPI to 240° next loop though; PPI to strongest convection @ 220° .
16:06 TOGA remaining in RAIN FAR but will switch back to RAIN NEAR soon.
16:10 Synched up fine, RHI to 227° this loop; convection forming a bent SW-NE line, with the northern part in the W. lobe.
16:20 RHI to 231° ; peak Zh ~ 45 – 50 dBZ, Synch OK.
16:26 S. end of line oriented for ~ 100 km NW to SE, but 80 km out it doglegs back toward NE; peak Zh ~ 50 dBZ near joint; RHI show tops ~ 10 km at best, most of cores < 5 km, as has been the case today in general; moreF dp shift aloft than below in some RHI’s.
16:30 Synch OK; North of dog leg is inside W. lobe, south of block mostly.
16:40 Synch OK, north part of line, the part in the west lobe, is becoming more stratiform, RHI to 233° .
16:50 Synch OK, RHI to 235° .
16:58 Storm continues to dissipate.
17:00 Synch OK; This’ll be the last volume as the case continues to marginalize.
17:02 Radar crashed or something.
17:05 Back running it appears; lost ~ 3 minutes of data; scope is clearing out now; this line is about the only thing left and it’s dissipating.
17:10 Running 10-TILT surveillance.
18:18 Conditions continue to clear.
18:40 Radar stopped for CALS.
18:59 Restarted 10-TILT SURVEY.
21:00 Re-start TRMM4.SCN, SURVEY2 (10-TILT 360° ). Small, scattered convective cells.
22:20 Starting TRMM6.SCN, LOOP MESO FR DD W. PPI centered at 250° AZ; RHI centered at 275° AZ.
23:02 Changed RHI center to 245° AZ to follow cell, @ 245° AZ, 30 km range, 42 dBZ.
23:30 Changed RHI center to 235° AZ to follow cell, @ 45 dBZ.
23:56 Changed RHI center to 260° AZ to pick up new cell 260° AZ, < 20 km, @ 40 dBZ.
February 4, 1999
00:20 Re-start TRMM6.SCN, LOOP MESO FR DD W to synch back to 10 minute marks. Scattered convective cells.
00:50 Starting TRMM4.SCN, SURVEY2 (10-tilt 360
01:10 Starting TRMM3.SCN, LOOP NEAR POL SEC. PPI centered at 150° AZ; RHI centered at 140° AZ. Large stratiform centered at 150° AZ, 40-120 km range. Small intense cell at 140° AZ, 20 km, 50 dBZ.
01:58 Changed RHI to 160° AZ. Small cell @ 160° AZ, 30 km, @ 40 dBZ.
02:30 Starting TRMM4.SCN, SURVEY2 (10-TILT 360° ). Most activity dissipating. One large cell to the NW, 120 km, @ 25 dBZ.
04:00 Dissipating stratiform moving NW into W. lobe., weakening convection 100 km NNW of S-POL.
06:00 Continued with TRMM4.SCN, SURVEY2 (10-TILT 360° ),
06:14 Stretched out the elevational spacing of top four elevations to 1.5° from 1.2° , to better top weak showers at closer range.
07:52 Stopped antenna briefly to switch to different antenna control software.
08:12 Almost no activity within 80 km.
09:12 Isolated N-S line of precip in center of E. lobe.
10:02 Convection starting to spring in north half of eastern lobe (> 60 km away).
10:11 Bird burst 40 km due north. Looks like they’re taking off right before a strengthening N-S line wipes through their location from the east.
10:03 Zdr is +bias on left side and –bias on right side of high |Ñ Zh| areas.
11:07 Storm tops around 10 km AGL but with radial velocity signature of upper level divergence.
11:11 Storm line almost an exact radial at 15° azimuth from 25-130 km range. Max Zh ~ 40 dBZ.
11:22 Max Zh of isolated cell now 50 dBZ. 35 dBZ to 8 km AGL.
11:26 Two areas of interest: one at 15° azimuth and one at 110° /75km. Both are topped fine with 360° surveillance save for a bit of the nearby southern edge of N-S radial line.
11:22? GoodF dp shift in isolated cell ~ 20° /5 km.
11:31 Zdr ~ 2.5 dB in isolated cell.
11:40 Isolated cell storm top to 13 km. Switching to 135° sector to assure toppage (trmm6.scn). Center 70° and elevation angle to 15.8° .
11:50 Center 65° to fully capture line to the north.
12:02 RHI’s to 5° this loop.
12:11 Started 10-TILT 360’s; sector not big enough to cover both storms. N. line ~ 40 dBZ max (at best, mostly 20-30 dBZ), 5-6 km deep.
12:20 Re-started surveillance, synched on 10’s, just in case some brave soul wants to do D-Dop on north line, which is still mostly in E. lobe; Given peak Zh and depth, it’s a pretty marginal case. It’s level of organization given it’s lack of intensity is intriguing, however.
12:30 Synched OK; SE looks like it’s weakening; N. storm maybe a bit weaker than before.
12:40 Resynched; continue to top everything.
12:55 Doing e-mail; missed synch but I’m sure it was fine.
13:00 Resynched but stuff is looking pretty sickly now; not going to worry about it from now on.
13:22 Short E-W line popped up just north of S-POL; nothing special just yet.
14:12 Mostly scattered weak activity to SE; 360’s continue.
15:03 Convection remains shallow, small, and popcornish.
16:00 Popcorn continues; bit more organization but everything’s pretty far away; 3 main areas of convection: to S., E, and NW out near 100 km of range.
16:22 Light rain @ S-POL.
16:29 10.7° continues to top everything basically.
16:31 Started loop survey RHI to cover @ 95° , 45 km; peak Zh ~ 50 dBZ but it’s small.
16:40 Typically intense but shallow cell, Zh > 50 dBZ, Zdr ~ 2+ dB, but tops < 8 km.
16:41 Running 10-tilt survey to 10.7° again.
17:04 Running LOOP SURVEY RHI with RHI to 90° to cover continued convection ~ 40-45 km out.
17:14 RHI shows convection to be weaker than before; back to 10-tilt 360’s.
17:33 Switching to SURVEY/RHI next loop. RHI on storm near TOGA, ~ 70 km , 337° . Smallish still, but respectable intensity.
17:34 Starting SURVEY/RHI.
17:36 There is a complex ranging 80-120 km @ 110° , with large anvil and Zh ~ 50 dBZ, but it’s cores get topped about 4° elevation.
17:42 Same old same old on RHI; Tops to 10 km, most of core below 5 km.
17:44 RHI to 116° to cover that storm complex to SE.
17:52 Tops to 10-12 km but core is very vertically developed; likely electrified.
17:54 Stopped; running HI RES FAR DD on 116° to cover storm; not synched since not in lobes; sector to 100° next loop to get more of anvil streaming to north.
17:59 Main core pretty large, about 95 km out, peak Zh > 55 dBZ.
18:09 Storm continues to look better at upper angles than the lowest. Good phase shift; anvil streams off ~ 100 km to north; PPI to 90° next loop to get more of anvil; however, this will clip small storm @ 50 km, 140° ; oh well, there are other small cells being scanned too.
18:15 This sector puts storm too close to right azimuth; going back to 100° next volume.
18:25 This storm @ 140° , 50 km is looking better; shifting sector to 110° next loop to cover more of it.
18:29 Still goodF dp, Zh in main storm.
18:30 Still not getting optimal coverage on near storm; PPI to 115° next loop.
18:33 Nice long (100 km+) arc of weak convection NW of TOGA, but SE storms are better for now.
18:34 Main storm starting to link up with cells SE of it to form NW-SE line that extends off scope; PPI to 120° next volume to correct for motion of near storm.
18:44 PPI to 135° to finally center things.
18:54 Storm very much linear now with near cell threatening to link up with the line; still going strong.
19:04 Remains a nice looking convective line, although S. half which goes off scope not all that strong; N. portion has the strongest cells.
19:25 Main storm continues to be intense main core ~ 85 km away.
19:29 Stopped; running RHI on main core.
19:30 Messed up azimuth of RHIs, now running properly on 138° ; anvil extends over 60 km toward radar. Vertical structure of cores still intense.
19:33 Running 2-TILT 360; phase shift through main storm has increased a bit; near cell has collapsed, but new cells have sprung up, which arc from its former position to main storm; PPI to 145° to account for movement and development.
19:35 Restarted volume loop; just noticed RHI showed NegativeF dp shift aloft.
19:45 PPI to 150° next volume.
19:49 S. Edge of storm starting to look a bit stronger than north end, at least @ low levels.
19:54 Still goodF dp, Zh > 50 dBZ; PPI to 155° next loop; main storm basically extends from 60 to 120 km out with two main cores, one at north end and one @ south.
21:00 Start trmm3.scn, loop far polsec. PPI centered at 160° ; RHI centered at 170° AZ. Storm centered at 160° AZ, 30-150 km range, up to 55 dBZ. Isolated cells to the west and NW.
21:17 RHI centered to 177° AZ to pick up some stronger reflectivities, @ 50 dBZ.
22:00 Synched up with TOGA on MESO DD E running TRMM6.SCN, LOOP MESOFR DD E. Cells forming up at @ 45° AZ, 30-40 km @ 40 dBZ; RHI centered at 45° AZ.
22:24 Changed RHI to 65° AZ to pick up the cell better, 40 km range, @ 40 dBZ. TOGA will go off of their DD scan at 22:30.
22:29 Nice cell (small) at 67° AZ, 60 km range @ 55 dBZ.
22:40 Start TRMM4.SCN, LOOP SURVEY RHI1. RHI centered at 150° AZ. Cell at 150° AZ, 120 km range, up to 50 dBZ.
22:50 Changed RHI center to 250° AZ to pick up larger cell, 60-120 km range with 50 dBZ.
23:21 Changed RHI center to 245° to follow slight shift in storm.
23:40 Start TRMM6.SCN, LOOP MESOFR DD W. RHI centered at 247° AZ. Activity developing WSW @ 40 dBZ, 60-120 km range.
February 5, 1999
00:06 Talked to TOGA, they are going to stay on volume, surveillance scan. Storm developing between 210
00:20 Changed RHI to 235° AZ to center on storm better.
00:40 Start TRMM4.SCN LOOP SURVEYRHI1 (RHI to 45° AZ). Activity to the west is diminishing; activity to the NE @ 45° AZ, 90 km range with 45 dBZ.
01:20 Start TRMM4.SCN, SURVEY2 (10-TILT 360). Most activity dissipating. Stratiform activity in the NE.
03:45 Lightning to SE: 1 min-1.
03:54 14 km AGL storm tops. Upper level elevations show anvil surrounding the strong cell with a ring of clear air next to the cell (compensating subsidence?).
04:02 Will switch to a sector centered on 100° . TRMM6.SCN, LOOP MESOFR DD E.
04:15 No visible lightning.
04:16 1 flash. RHI’s show 40’s dBZ above freezing level as expected if electrified.
04:20 Structure less isolated now, elongating into N-S shapes. Visible lightning to SE (very attentive visual lightning counts below. HH:MM: # near flashes (# distant flashes)
04:56 04:24: 0, 04:25: 2, 04:26: 1, 04:27:3, 04:28: 2, 04:29: 1, 04:30: 2, 04:31: 2, 04:32: 0, 04:33: 2, 04:34: 0 (1), 04:35: 2, 04:36: 1, 04:37: 1 (1), 04:38: 1, 04:39: 2, 04:40: 2, 04:41: 3, 04:42: 2 (1), 04:43: 2, 04:44: 2, 04:45: 3 (1), 04:46: 2, 04:47: 1, 04:48: 2, 04:49: 1, 04:50: 2 (1), 04:51: 2, 04:52: 1, 04:53: 2, (note: a lot of flashes come in pairs), 04:54: 2, 04:55: 1, 04:56; 1
05:00 Moved center to 110° (of 135° sector). Don’t know what flat plate screen is supposed to look like during a stroke. However, I can’t see anything blipping on it.
05:17 More visible count of flashes toward SE: 05:09: 1, 05:10: 1, 05:11: 1, 05:12: 2, 05:13: 1, 05:14: 1, 05:15: 0, 05:16: 1, 05:17: 1
07:03 Did 135° sector scans toward the SE for two hours. Activity is just slowly weakening. Nothing else in the scope.
07:50 Everything dissipated. Changing to TRMM4.SCN, SURVEY2 (10-TILT 360’s).
08:40 Zebra machines froze up. But we just rebooted them. Just noticed that the DORADE writer has been hung also (Raw data has still been coming through however).
10:30 Awesome multiple bird bursts. 2 big ones and 6 or more weaker ones. Otherwise, not much to speak of weatherwise. Another day is dawning while I am yawning.
10:25 We’ve got a 15 dBZ sun 5° elevation, 110° azimuth.
12:10 Everything is pretty clear, other than patches of fog. Continuing with the 360 surveillance scan (10-TILT).
14:17 Continuing with surveillance scan/radar screen is clear.
14:44 ER-2 flight today is a go. They should be there at about 19:20.
15:04 There is some development to the SW, centered at about 125 km, 192° . Reflectivities are 40-45 dBZ at the peaks, Zdr = 1.5 to 2 dB.
15:12 There are four distinct cores in this region with peaks close to 50 dBZ. There are high Zdr signatures at the peaks of 2.5 dB. Will use an RHI on next scan to take a closer look. Echo tops look to be 9-10 km.
15:20 Running survey using up to 10° in elevation, with an RHI scan centered at 191° .
15:36 Small, weak convective cells are now starting to show up mainly to the east @ 126 km and to the west/SW @ 145 km.
15:38 The convective cells to the SW are becoming less distinct and are merging together. The intensity of the largest cell is the same as at 15:12. Echo tops remain for the most part 10 km AGL or less.
16:20 I don’t think this is worth any more RHI’s as of right now; will go back to 10-TILT 360 SURVEY at the half hour.
16:38 Small pockets of convection are starting to pop up in various places now.
16:45 A line of possible development in the eastern dd lobe is appearing – not much now but will keep an eye on it. Run almost along the 45° radial from the radar to the edge of the dd boundary.
17:24 ER2 is up and heading this way; should be in radio contact within 30 minutes.
17:25 The line in the eastern DD lobe seems to be building.
17:35 Talked with TOGA; going to synch up at 17:40, running MESO DD E NEAR. The PPI will be centered at 47° .
17:40 Start MESO DD E NEAR scan, adjusted sector to be centered at 52° .
17:43 Peak reflectivities in this line are approaching 50 dBZ. The southern point of the line is ~ 22 km east of the radar. The line is N/S.
18:02 The ER-2 will be flying a line right along the activity forming to the east of S-POL.
18:04 Peak reflectivity now exceeds 50 dBZ (~52 dBZ).
18:11 Now seeing some higher Zdr’s ~ 2 – 2.4 dBZ. Reflectivities at peaks along the line at or just exceeding 50 dBZ. ER-2 has spotted the line and is on station.
18:14 Things seem to be falling in place for a good DD scan. We are synched with TOGA and the ER-2 is working the line.
18:16 ER-2 reporting to be at end of line. He will be turning around and coming back down the line a little further west.
18:20 Had to resnych DD scan; was > 25 sec off.
18:26 Line is moving toward the profiler site. Keeping fingers crossed, maybe we will finally get a decent profiler case.
18:28 ER-2 is over center of line on his south bound leg.
18:31 There are some scattered Zdr in the peak reflectivity regions that are close to or exceeding 3 dB.
18:38 ER-2 is starting a bow-tie formation over the profiler site. The line of activity has not yet reached the profiler site.
18:39 Shifting the sector center to 80° to make sure we are covering profiler site.
18:50 Will have to resynch on next 10’s.
18:51 Line of activity seems to be holding together with cells still growing. Reflectivities are still around 48-50 dBZ in peak areas. Cloud tops are above or near 12 km in height.
19:02 Cells that are part of the line near S-POL are dissipating.
19:10 Sector scan centered at 70° .
19:16 ER-2 over center point of bow-tie, reports that clouds are still ‘bubbling up.’
19:17 The southern part is dissipating, while the echo seems to be growing further to the north.
19:25 Ran an RHI centered at 24° (19-29° ) JA RHI SECTOR over profiler site.
19:28 Run 2-TILT 360 to get surveillance scan.
19:30 Synch back on DD scan about 25 s off.
19:33 I have been shifting sector scans to keep up with activity. I may have forgotten to record center points in the log now at 65° .
19:35 Starting another RHI (same as 19:25).
19:38 Running 2-TILT 360° to get surveillance scan.
19:40 Synched back to MESO DD E NEAR SCAN, centered @ 60° off by ~ 20 s.
19:47 In case I haven’t indicated previously, the ER-2 is still working the N/S line of activity.
19:50 Looking at larger picture to decide what to work next. Profiler area looks to be clear.
19:54 ER-2 reports center point (profiler) is clear under him.
20:31 Cell that ER-2 is working on is at 70° AZ, 60 km with respect to TOGA. We are currently running TRMM1.SCN, LOOP MESO DD E centered at 20° AZ. Small cell at 70 km, 20° AZ, with respect to S-POL, with 50 dBZ max. Cannot get TOGA on the phone.
20:46 Starting TRMM1.SCN, JA RHJI centered at 15° AZ.
20:49 Start 2-TILT 360° .
20:51 Start TRMM1.SCN, LOOP MESO DD E centered at 20° AZ.
20:58 Start 2-TILT 360° .
21:00 Start TRMM1.SCN, LOOP MESO DD E to resynch on 10 minute marks. Cell at 20° AZ, 80 km range, @ 45 dBZ. Called TOGA, confirmed that they are still on DD, on cell at 20° AZ, 80 km.
22:17 TOGA is back on volume surveillance. Start 2-TILT 360. Isolated convective cells, most activity to the north is breaking up. Nice cell to the south @ 197° AZ, 85 km range, @ 50 dBZ.
22:20 Start TRMM4.SCN, LOOP SURVEY RHI, RHI centered at 197° AZ. Isolated scattered cells nice cell at 197° AZ, 85 km range, @ 50 dBZ.
22:36 Start 2-TILT 360° .
22:40 Start TRMM3.SCN, LOOP FAR POLSEC. PPI centered at 210° AZ. RHI centered at 205° AZ. Activity starting to develop to the SW. 210° AZ, 60-120 km range, 52 dBZ, max echo tops 10-11 km.
23:41 Changed RHI center to 199° AZ. Reflectivity @ 50 dBZ, 120 km range, 199° AZ, Zdr ~ 3.0 dB.
February 6, 1999
00:53 Changed RHI center to 127
00:56 Changed PPI center to 120° AZ. Small thin line developing @ 127° AZ with 50 dBZ max, extends 20-100 km range. Larger cell at 135° AZ, > 120 km range @ 40 dBZ. Most other activity is dissipating.
01:31 Start TRMM4.SCN, SURVEY 2.
01:40 Restart SURVEY1 to hit 10 minute marks. Most activity scattered and dissipating.
03:10 Restart SURVEY2; small cell to the SE; mostly clear otherwise.
03:45 To the SE, one lightning flash every 5 minutes or so.
04:08 Starting HI RES shots of convection to NW. TRMM6.SCN, 90° sector, 15 elevation angles, centered on 330° azimuth. Rain over gauge network #2.
04:14 Re-centered on 335° azimuth. There’s some convection still 120 km to our SE that isn’t covered by sector scans, but oh well.
04:23 Top to 10 km in cell 50 km to NNE.
04:28 No lightning out there for 5 minutes that I checked. Cell is relatively narrow and leaned over to the left (west). The flat plate is on to detect anything peculiar, like lightning.
05:04 tops to 12 km AGL. Max Zdr ~ 2 dB. Flat plate timer says 06:13 but it’s really 05;12. The bottom field line seems to wiggle downward a little bit now.
05:20 Added an elevation angle (17.3° ) and shorted the sector to 85° in order to top the stuff. I figured even if rain gauge network #2 is getting dumped on, you don’t need to run the TRMM2.SCN because the HI RES DD gets low elevation scans every 4 minutes anyway. Need to top the storm anyway, so this setup is good. 85° sector, 16 tilts, up to 17.3° elev.
05:29 Upper level scans outline an echo as if the outflow is spiraling outward.
05:33 100 km to east a bunch of cells sprung up aligned.
05:41 No more heavy rain indicated in cell to NW will switch to surveillance scans. Clipped 0.7° deg 360° scan.
05:50 Switched to 360° surveillance.
12:02 Stopped for calibration.
12:46 Restarted SURVEY2 10-TILT.
13:24 Darn near nothing out there…
13:27 To 5-TILT SURV next loop.
14:27 Scattered weak convection popping up. Going back to 10-TILT next loop.
16:06 Widespread popcorn convection continues; 10-TILT SURVEY continues.
17:10 10.7° continues to top just about everything; S. convection has organized and strengthened into a small non-linear system but it is ³ 120 km away.
17:19 Running LOOP SURVEY RHI through S. storm @ 193° .
17:29 Tops > 12 km with some cells > 30 dBZ to 8 km, so not too bad of a storm but distance is awful.
17:41 RHI to 195° this loop; SE cell @ 175° or so looks strongest right now but it is almost off the scope.
17:51 RHI to 178° to cover stronger cell; but we’re pushing it now.
17:57 S. storms are nice still but too far away to care; I suspect they are electrified.
17:59 Restarted 10-TILT SURV
18:41 Have some better convection to S.
18:43 Beginning HI RES 4-MIN SECTORS on S. storm, centered on 180° ; storm consists of a loosely organized complex of cells; one cell @ 171° , 75 km is strongest; peak Zh ~ 55 dBZ; storm well outside lobes so not synching.
18:52 There’s some stuff in the lobes but right now this is the strongest game in town.
19:12 Now W. side of storm looks better as the strong core on the E. side has collapsed.
19:17 Volumes to 185° next set.
19:22 New cell with 50 dBZ, but small, @ 45 km, 163° AZ; It is within the PPI sectors.
19:33 Newer close cells now strengthening while the older storm wanes.
19:44 Started LOOP FAR POLSEC on 135° to cover new convection (small cells) @ 105° , 95 km with 50 dBZ; continue to cover near storm @ 170° ; RHI to 106° . Not covering the now decaying original convection to the SSW anymore; most storms are pretty small today; nothing’s been really that exceptional.
20:30 Going to 360 surv. scan 10-TILT. A lot of scattered cells around and several outflow boundaries; no major organization yet.
22:25 There is some activity in the W DD lobe. Nothing real organized, just small pockets of convection. A cell near the edge of the DD W lobe (96 km, 29° ) is weakening.
22:30 Running MESO DD W centered at 260° with the RHI centered at 275° .
22:35 Looking at a cluster of cells just to the SW of S-POL, starting at about 40 km. Peak Zh’s are about 40-45 dBZ. My RHI missed the cluster. Adjusting RHI to 238° . Sector centered to 245° .
22:47 Differential reflectivity values range up to 2 dB. Not muchF dp as these are small in nature. LDR is right around –26 to –28 dB.
23:02 Adjusting RHI to 255° .
23:04 Going to MESO DD W NEAR on next 10’s.
23:10 Running DD MESO W near at 245° .
23:16 Looked outside, there are lightning flashes, but are few (about 1 min apart).
23:19 The cells have formed a small line just to the SW of S-POL starting at 21 km, 245° and going to 74 km, 248° . Peak Zh’s near 50 dBZ. Average values around 38-40 dBZ. Zdr’s around 2.5 dB in the peak Zh areas.
23:25 Talked to TOGA, we are going to do HIGH RES scans starting at bottom of the hour.
23:30 Center at 237° ; RHI at 254° ; Synched with TOGA, running HIGH RES NEAR DD.
23:43 Echo tops are at 12-13 km, centering RHI at 251° .
23:52 Still have peak Zh of 50 dBZ and Zdr of 2.5-3 dB in this line. HIGH RES SCAN is topping it OK.
February 7, 1999
00:00 Talked with TOGA; will continue to do HIGH RES scans at least until bottom of the hour.
00:20 Resynching HIGH RES scan.
00:25 Zebra crashed and machines needed to be rebooted.
00:30 Switch to MESO DD E NEAR centered at 240
01:13 Zebra is back up and running. LINUX was detecting bad sectors and wouldn’t allow a reboot until they were cleaned up.
01:14 Shifting my sector scans to 250° trying to get the cell just west of TOGA radar. Peak of cell is around 45 dBZ with low Zdr at Zh peak » 1.5 dB.
01:20 Resynching MESO DD W.
01:21 Now has both complexes in DD scan.
01:47 TOGA called; said there was a lot of lightning in the system to their west.
02:30 There is a lot of activity in the west DD lobe so I’m staying with the 135° MESO DD W NEAR to cover everything. New activity has developed just to the west of S-POL with 40-45 dBZ Zh and 0.5 to 1.5 dB Zdr.
02:54 Hearing some thunder. Presumably from the cell to our west. Sector scans are now centered at 260° .
02:57 Running an RHI through the cell to our west. Probably too close for the canned RHI but want to get an idea of what is happening.
02:58 Running 2-TILT 360° to get survey in. I will be late for the MESO DD W NEAR scan.
03:01 Started MESO DD W again (1 min late). Will resynch at 03:10.
03:02 A new line of activity has developed to the SE of S-POL at about 40 km, 160° .
03:07 Running 2-tilt 360° so I can resynch the DD scan in 3 min.
03:10 Re-synched MESO DD W (NEAR) scan (15 sec off).
03:22 The cell to the SE has strengthened, but is outside the DD lobes. The cell just to the west of S-POL has moved a bit to the SW. It still has 40-45 dBZ Zh values so I will keep the sector scan inside the DD W lobe, for now.
08:57 Switched to SURVEY.
12:02 Stratiform region in the SE portion of DD W lobe. At 12:10, will start sector scans (MESO DD W FAR), centered at 230° . An RHI will be centered at 222° .
12:08 Running 2-tilt 360° . Tables got mixed up when I was setting up the meso scan.
12:10 Synched MESO DD W (FAR).
12:26 Reflectivities range from 30 to 35 dBZ. Zdr» 0.5 – 1.0 dB. Shifted RHI to 202° .
13:28 The stratiform precipitation in the SW is hanging in there. Average Zh is still around 30-35 dBZ. Will continue with sector scans.
13:36 Latest surveillance scan shows small convective cells developing in the NE.
14:21 Continuing with sector scans centered at 230° . Probably will switch to surveillance scans sometime soon. The stratiform area is still in the W DD LOBE but nearing the edge and weakening somewhat.
14:40 Going to 10-TILT 360’s.
14:44 Quite few more smaller cells have popped up to the E and NE.
15:37 Still in 360’s 10-TILT. Not much has changed; still small pockets of convection in the N and NE.
16:00 ER-2 is going up today and should be in radio contact in about an hour and fifteen minutes.
16:03 Some of the smaller convective cells are starting to link up in the DD east lobe. Forming an E/W line 73 km N of S-POL. Reflectivities are» 35 dBZ along line with some 40 dBZ peaks. This is a thin line.
16:10 There’s a system moving in at 140 km, not very strong but shows some organization. General movement is from NE to SW.
16:14 Think I will start DD E scans at 20 past.
16:20 Start MESO DD E (FAR) LOOP centered at 22° . The RHI is centered at 25° .
17:17 Waiting for ER-2 to arrive. The line that developed to the N is moving toward profiler. Tentative plan is to have ER-2 do a bow-tie over profiler site.
17:30 Adjust sector scan to cover the rain gauge sites centered at 12° . Next RHI is 25° to look at profiler site. Previous scans also covered rain gauge network #4 but wasn’t sure. At any rate, needed to shift scans to keep up with movement of lines.
17:38 ER-2 has made radio contact.
17:50 Began a MESO DD E (NEAR). Talked with TOGA. We should be synched with them. ER2 91 mi from start point of line (L1). Sector is centered at 12° .
17:57 Echo tops go to at least 12 km. All the reflectivity is close t the ground, upper level of clouds – nothing there.
18:02 ER2 is 30 sec from start line. A NW to SE line has formed. Peak reflectivities are near 45 dBZ. The line is just north of TOGA and the main portion is just to the NW of S-POL. Some 3 dB Zdr.
18:13 50 dBZ over TOGA site at 8 km. All four rain networks are seeing rain. Sector scan is covering all 4 sites.
18:21 See» 60° of phase shift along 318° radial. The line of activity is mainly along the 318° radial.
18:56 ER2 is moving to second target which is centered at S10° 49’ and W61° 33’. Doing a bow tie. The cell is centered at 47° AZ, ranging in distance from 46 km to 90 km. Peak reflectivity is at 74 km » 48 dBZ. Zdr » 0.5 – 1.0 dB.
19:03 ER2 reporting good run on his first bowtie leg.
19:06 ER2 is on the second line of his bowtie.
19:11 This cell has an average 40 dBZ reflectivity, 45 dBZ peak reflectivity. ER2 will be repeating bowtie. TOGA is still doing 135° sector scans. Lightning near S-POL. This cell should be good series of measurements, seeing good reflectivity at high altitudes » 40 dBZ. With peak Zh, we saw very little Zdr enhancement (1.0 to 1.5 dB).
19:20 Will need to resynch MESO scan; want to add some RHI’s here, so will interrupt our MESO scans for this then resynch at 19:30. We are topping the particular cell we are looking at so this shouldn’t be a problem.
19:30 Resynched MESO DD E (NEAR) scan. The scan is topping everything. Rethinking our next step.
19:40 Switching to MESO DD E (FAR). Near was topping everything (almost a minute off resynch on next scan).
19:51 Restarted sequence (a little late). RHI’s cut-off.
19:57 Noted that Zdr’s are significantly higher in front line cells but not noticeable in trailing cells.
20:00 Resynching exactly. ER-2 doing bow-tie’s in eastern lobe. Keeping on decaying precip.
20:17 Losing comm. With ER2! Only temporary.
20:24 Recentered sector to 20° ; RHI’s to 84° . This will cover strongest cell in the area.
20:30 Recentered sector to 30° . Considering centering on 60° . Too bad the deep convection 90 km to the SE is not in the DD lobe or under the ER-2. It’s probably only observable by S-POL. No flat plate antenna, profiler, etc. So what we are doing is the best. Centered RHI’s on 130° to capture really deep convection. Moving the ER-2 over it. 20 mile bow-tie pattern. Will move sector there too.
20:45 Center on 88° azimuth. TOGA will keep on sectoring til 21:00 and then return to normal surveillance.
20:50 55 dBZ in core 15 km high, 40 dBZ to 6 km, 35 dBZ to 9 km.
21:00 Recentered 135° sector on 95° . Tops to 16.8 km in strongest part.
21:15 Recentered to 100° azimuth.
21:19 Good divergent outflow and slightly overshooting top.
21:40 Re-centered on 120° - ignoring stratiform for now. But will switch to 360° surveillance soon.
21:43 Zdr is 2 or higher in dinky cells above the gust front, but low otherwise.
21:50 Switched to SURVEY 2 (360° ’s up to 10.5° ). Want to capture full region and nothing convective is within 40 km, so most will be topped.
22:00 Reset storm accumulations on ZEBRA computers.
22:17 Blockage is leading to horribly negative Zdr from 252-270° azimuth.
22:47 More and more bright band signatures developing. Every so often a big patch of high Zdr appears in a stratiform region slightly above the freezing level (2145-2300) Zdr 3-4 dB. Patches of strong convection persist ~ 100 km south of S-POL.
23:41 Lightning associated with convection 120 km to the south about 2-3 flashes per minute, visually.
February 8, 1999
01:40 Not much out there except decaying stratiform in NE quad and S quad. Continuing 360
03:07 Wimpy cluster of cells about 50 km to the west recently developed. Probably only 6 or 7 km AGL radar cloud tops.
03:24 Weird Zdr pattern again in weak stratiform precipitation in vicinity of melt level and above (e.g., see 3.5° elevation angle tilt). General pattern has a patch of near zero Zdr, with negative values on the right and positive on the left (relative to direction of beam). Beam mismatch/Zh gradient problem?
03:50 Synched 360’s at 20 seconds past.
13:40 360° ’s 10-TILT have been run up to this time.
13:42 There are a few clouds to the N with 20 dBZ reflectivities, little else is occurring.
14:14 Real time display froze up. Had to reset computer. Radar was stopped for approx. 5 mins. Need to resynch survey scan at 30 past.
15:48 Continuing with 10-TILT 360° ’s; not much out there right now.
16:32 Some scattered pockets of convection are starting to appear. Most notably in the S-SW, but some also in the north.
17:35 10-TILT 360° ’s. No major developments. The small areas of convection in the DD W lobe are still present. There seems to be some grouping but nothing major yet. There also may be a line of cells grouping together SE of S-POL. Will keep an eye on both of these areas.
18:04 Not much is developing from the group of cells in the DD W lobe. Also the line to the SE of S-POL doesn’t seem to be hanging together.
18:53 ER2 is enroute and Citation is going up. Estimate arrival for ER2 is 19:30.
19:28 Things aren’t cooperating, so far no interesting developments for planes to cover.
19:34 ER2 has made radio contact.
19:57 ER2 will fly over ½ forest and ½ pasture to get characteristics of boundary layer/soil with radiative flux instruments.
20:06 ER2 should be overhead. No radio contact with Citation yet.
20:29 Radar loop shows the clear spots where the boundary layer was cooled by previous convection. They eventually recover and cloud streets emerge in their place.
20:47 Citation finally made radio contact. They will fly through the boundary layer, if given clearance to fly that low (700 m AGL or so).
21:25 Citation spiraling down over TOGA site to start leg through boundary layer to the forest site.
February 9, 1999
01:40 Whole lotta nothing out there.
01:50 5-TILT 360
13:30 Not much happening. Still running surveillance scans (2-TILT right now). Will switch to 5-TILT 360° ’s.
14:25 5-TILT 360’s.
15:18 There are some convective cells to the SE at about 124 km. Also some development to the NW at» 125 km. Some very small scattered pockets of convection in the DD W lobe.
15:45 The development in the NW is starting to form a NE to SW line. The reflectivity peaks are close to 45 dBZ. Zdr» 1.5 – 2.5 dB.
15:53 The cell to the SE is growing a bit. Zh peaks around 45 dBZ. Zdr peaks around 2.5 dB. Some cells are developing in the west DD lobe and seem to be increasing in strength.
16:03 Going to run an RHI through the cells in the DD W lobe to get a better look. Centered at 249° . The main cells that I was looking are beginning to weaken.
16:17 Looks like there may be a group of cells in the DD E lobe (northern edge) that may be trying to form a NW to SE line starting at 128 km, 13° wrt S-POL.
16:30 Doing an RHI through the cell to the east 120 km, centered at 94° . There seems to be quite a bit of development today.
16:43 Ran an RHI through cell just to the East of S-POL at 20 km. High Zh, low Zdr (45 dBZ, 0.5 – 1.5 dB). The are a group of convective cells to the SE centered at 36 km.
16:51 RHI snapshot (97° ) caught an interesting measurement. A core of 40-45 dBZ built up just before collapsing? These group of small cells to the SE are interesting to loot at.
17:01 An RHI through 101° shows an increase in LDR to –18 dB. This is the first I’ve seen this down here! Zh peaks at 55 dB, Zdr » 0 (above freezing level). Peak Zh at 8 km of 50 dBZ, cloud top at 9 km!
17:13 Caught the above at just the right time. This thing went fast.
17:20 Starting POLSEC scan on the area to the SE of S-POL centered at 135° , with an RHI centered at 154° . Right now this looks like the most interesting area to look at.
17:30 POLSEC scan picking up good data. We are again seeing enhanced LDR values above the melting layer. LDR of –20 dB, just above a peak Zh region of 55 – some 60 dBZ. In the peak Zh area, Zdr peaked at 3.5 dB.
17:53 Continuing with 120° POLSEC. The main cell of interest is centered at 52 km, 166° .
17:59 OK, this is different. We have a core with 60 dBZ, LDR of –18 to –16 dB, Zdr at the peak Zh is –0.5 dB! Peak Zdr below melting layer is 3.5 dB. We have ice.
18:17 Staying with the POLSEC loop as long as we are seeing these interesting polarimetric signatures.
18:40 POLSEC FAR scans. Still on the same cell which is weakening a bit. It is now pretty much south of S-POL.
18:45 Citation will be flying today. Should be in area at around 19:30. Talked with TOGA. We are going to start sector scans MESO DD W (FAR) at 19:00.
19:00 Synched with TOGA on the MESO DD W FAR scan centered at 270° . RHI is centered at 277° . There are a couple of cells in the west lobe that we are looking at. 280° , 95 km and 300° , 55 km. 10-11 km echo tops on the cell at 55 km.
19:08 Cell at (98 km 280° ) close to 50 dBZ reflectivities, 2.5 dB for Zdr’s.
19:23 The cells that we were looking at in the western lobe are dying off. As is a lot of the other stuff in the region.
19:30 Moving back to 10-TILT 360° surveillance scans.
19:54 Citation has made contact.
20:02 Told Citation to check out clouds 60 km to our north. Keeping TOGA updated on plane also.
20:15 Told Citation to look for a tower and keep us updated. Stratiform anvils are thin and extensive and blown off to the NW for 100+ km.
20:19 Talked to TOGA. They are keeping in surveillance mode until we call about a convective target. TOGA’s desk phone is not operable, so we’ll use the cell phone number. If TOGA is topping cells, then they don’t need to go into sectors, even if the aircraft is flying.
20:35 Talked to TOGA. Desk phone is working now. They are topping cells just fine. Aircraft is 40 km north of TOGA sampling 8 km high cell with» 40 dBZ max Zh.
20:57 Taking out 10.7° elevation and adding RHI’s.
21:02 Will sector so we can top it soon. Moving Citation over nearby cells. 30 km to the NNW. New cells are very close. Will ask TOGA to do HI RES scans at 2120 on cells 10 km west.
21:19 RHI’s started. Cut off 360’s.
21:21 Started HI RES a little late (1 minute). Don’ know what it’s doing. The sequence is too long for 5 minutes
21:25 Started another 90° sector 270° azimuth.
21:29 Doing 1.1° 360° manually.
21:30 Manually starting 90° sector on 275° azimuth.
21:34 Same as 21:30.
21:38 Manually starting 1.1° 360° surveillance.
21:40 Manually starting 90° sector on 285° azimuth.
21:44 Manually starting 90° sector on 285° azimuth again.
21:50 Moving off 90° sectors. Moving to 10-tilt 360° surveillance. So is TOGA.
21:54 Will switch to 135° MESO DD NEAR sector on 22:00.
22:37 Doing 5 min HI RES updates with TOGA on 22:40. Running 360° surveillance first.
22:40 90° sectors centered on 265° azimuth for convective lifecycle study. Tops are around 12 km AGL.
22:44 Restarted 90° sector after reaching 21.6° on previous scan. Almost topped it all. We’re a little off center but we’re getting everything major included in the sector. Centered on 272° .
22:48 Running 1.1° 360° surveillance manually.
22:50:15 15 seconds late on 90° sector. 275° azimuth center.
22:54:50 280° center. Not quite topping it now.
22:58:40 360° surveillance 1.1° elevation.
23:00 Started 90° sector again.
23:04:24 Same as 23:00.
23:08:30 360° surveillance at 1.1° elevation.
23:10 Started 90° sector again. Cells are still raining hard, but coagulated. They haven’t moved much because they keep regenerating over the same place. Too bad there is serious beam blockage at those azimuths. Saw 3 flashes (over 3 minutes) about 1 /min around 23:10 from the western cells.
23:14 Another sector began. The last one topped it fairly well. This is a perfect electrification case study, assuming the flat plate is recording the flashes. Every significant part of convection is radar covered. The flat plate should be able to detect this range. The TOGA is synched for 2 volumes every 10 minutes. What more could you ask for?
23:18:30 Began 360° surveillance 1.1° elevation.
23:19:45 Began 90° sector again.
23:24:15 Same as last.
23:26:14 Actual lightning flash visually spotted in western stuff. Also unrelated flash way off to the north.
23:28 360° surveillance started.
23:29:40 Began 90° sector again. If flat plate antenna data doesn’t reveal flashes from such a close range (20-50 km), then the instrument is virtually useless. Hopefully, they will be gleaned from data after post-processing procedure, because nothing is evident on the flat plate monitor showing the "EKG"-like lines.
23:34:14 90° sector restarted.
23:38 360° surveillance.
23:40 Re-centering on 285° azimuth.
23:42 Gust front hit the S-POL (4 m s-1 surface winds).
23:44:40 90° sector again. Isolated cell popped up northeast of the main precipitation.
23:48:43 360° surveillance 1.1° elevation. Same…same…same.
February 10, 1999
00:12 Will throw an RHI in there through isolated cell. Not impressive at all. Everything is dying. There’s no overshooting top now. Or, at least the system is shorter than before.
00:16 Good phase shift aloft. (above freezing level).
00:42 TOGA and S-POL will come out of HIRES scans at 01:00. System is dead and is mostly anvil now. Some convection is out of range from S-POL, but just coming into range to the north of TOGA. Producing some lightning in the distance.
00:50 Turning off flat plate antenna program. Nothing looks worthy of electrification by a long-shot.
01:00 Moving to 10-tilt 360° ’s.
01:26 In various parts of NW quadrant, there’s very distant lightning. Total of ~ 3/min.
01:30 Will run 5-TILT 5-minute 360° ’s for a while. Everything would be topped still. Some convection is moving into range from 10° -30° azimuth (160 km range) max Zh 45-50 dBZ – not bad.
01:40 Adding elevation angle to 5-TILT volume (6-TILT) to make sure top that distant strong echo to the north. Looks like it’s ~ 15 km high. Now we will by unsynched with TOGA. But if it moves near the DD lobe I will restart volume scanning on the 10’s.
01:54 Going to construct 5-min sector scan for entering system.
01:58 135° sector centered on 15° azimuth with 7-TILTS.
02:00 TRMM3.SCN POLSEC 120° sector centered on 15° azimuth with RHI’s also.
02:18 Storm is too shallow to be worth sector scans. Lightning is not seen in it outside. So, moving back to 6-minute 6-TILT 360° SURVEILLANCE.
02:54 Moved to 5-TILTS, 5 minute scans.
06:28 Light cirrus to the southwest.
S-POL LOGBOOK #2: 2/10/99 - 2/28/99
February 10, 1999 (continued):
0400-0841 Yet another quiet night. Storms to the N and W slowly drifted Westward and died out. Watched some cirrus go by.
12:21 Switching to an 8-tilt Survey Scan (top el at 10° )
14:14 8-tilt Survey Scan
14:52 Dinky patches of isolated cells with elevated ref. about 40-160 km out with max. tops between 6 and 7 km AGL.
14:55 Not enough solid coverage over rain gauges yet to warrant trmm2.scn
15:10 Started rain gauge loop (trmm2.scn) #4 site may be getting some popcorn convective showers. ("measles showers")
15:20 Now isolated cell w/ 40 dBZ Zh at 135 km range, to the east. Also one at 100 km to the SW.
15:22 Widely scat. Popcorn cells cover NNW quad.
15:38 more cells popping to E at 125 km range.
15:40 Will move off of trmm2.scn in 10 min. Strong cell has grown to WNW at 65-70 km range. Max 50 dBZ. Don’t know its height yet because its only scanned at low levels so far.
15:50 Began 10-tilt 360° ’s up to 10.7° . More cells with 50 dBZ developed 120 km to the NNE.
Citation and ER2 should arrive at 1830.
15:55 Cell to west looks best so far. Zdr is 2+ dB. Core of 50+ dBZ is enlarging and up to 6km AGL. Eastern cells at 120km are ~ 12 km high. Western cell must be 13 or 14 km because it wasn’t topped at 10.7.
16:05 Signal processor must be restarted.
16:20 Talked to TOGA to test phones. It’s A-OK. Eastern deep convection has proliferated- along with NNE convection.
16:23 Good isolated cells 70km out to the SW also. We’re still topping everything with 10-tilt 360 surv. Scans but just barely. We’re synched on the 10’s with TOGA, I assume (at least we are).
16:27 Eastern area has one top up to 16km.
16:32 Zdr is high in various low level rain cores (3 dB).
16:34 W dd lobe has two spots of deep convection. E dd lobe has one in the distance. Wdd lobe has lots of blockage, of course.
17:07 Running an RHI through activity that is probably waning toward the west.
17:10 Going to survey with RHI centered at 20°
17:20 There some new cell development just to the NE starting at 27km and extending to ~ 102 km right along the 60 radial. Reflectivities close to 50 dBZ peaks.
17:39 13km Tops 40 dBZ up to 8km in the cells along the 60 radial.
17:40 Resynched scan.
17:41 ER2 and citation flying today. Trying to work up target area.
17:42 ER2 has made contact.
17:43 peak reflectivities were close to 55 dBZ. Zdr values approach 3dB 80-90 km , 257
17:44 There is widespread activity to the NE. The stuff to the east is turning into more of a stratiform type rain. There is strong activity to the SW at 80-90 km, 257
18:00 Starting dd e (near) centered at 45. Talked to Toga, they will synch up at 18:10 with 135 sectors
18:07 dd e near is not topping the cell closest to SPOL.
18:09 Planes are going over the profiler site.
18:15 Running RHI along a 6 radial as center. This has weakened a bit.
18:18 Running 2-tilt 360 to get surv.
18:20 Resynched on the dd e (near scan).
18:23 A lot of the heavier activity is just to the NE of SPOL.
18:30 Screwed up PPI scan. Going to resynch at 18:40. Probably about a minute or so late.
18:30 Accidentally introduce phi-dp cal scan.
18:40 Running an RHI at along the baseline between Toga and SPOL (wrong az!).
18:42 Switching 1.1 and .7 angles on 360’s. I can get this thing resynched.
18:50 Synched back with dd e near scan.
18:56 Running RHI first at 323 for TOGA comparison. Then moving to RHI entered around 0 for this case study. ER2 reporting ice in a cell he was working (graupel ).
19:00 Finally got a good synch for the dd e scan. TOGA is still doing 10 min scans. (sector).
19:05 ER2 and Citation working line running NW to SE along 330 radial.
19:13 Citation doing bowtie on strong cell 30km NNW of SPOL. Advised TOGA to cover it. They took the advice.
19:14 Starting RHI center 348.
19:20 Real time display needed to be rebooted. Will try to resynch at 19:30.
19:26 ER2 reports irregular ice crystals.
19:26 Running RHI centered at 335.
19:30 Resynched on meso dd e (near) scan ok.
19:36 Still working the NW to SE line approaching the baseline. Activity along this line is starting to weaken a bit.
19:46 Running an RHI at 326 center. This is more for comparison with TOGA.
19:50 Synched meso dd e (near).
19:55 We want to do an RHI between the 2 radars while the ER2 is flying the same line.
19:58 Started RHI scans with a center along the baseline.
19:59 Citation should be spiraling right down between the 2 radars.
20:00 Running 1.1 el 360 then will do another set of RHI’s.
20:03 Doing RHI’s again along the baseline.
20:05 Started a late meso dd e scan, because of the RHI’s needed along the baseline. Actually everything in the sector has died so the scan (sectors may be worthless anyway).
20:11 Switching to 120 Polsec to cover activity to SE. Centered at 135. RHI is currently centered at 135 also. Not synched up well but not that important cause we are out of dd lobes.
20:20 Started a 120 Polsec (far). Two RHI’s in this loop and are centered at 135. The ER2 will be working a stratiform region to SE.
20:25 Still doing 120 Sec (far) w/ Two RHI’s all centered at 135.
20:37 ER2 is still flying in stratiform to SE of SPOL. Next RHI’s will be centered at 143, sector still at 135.
20:47 RHI’s show great signal of melting level in many variables (dBZ, VR, Zdr, LDR).
20:50 Started sector on the 50. Besides stratiform area to SE, 80-120 km away, strong storm at 40-60km with some noticeable visible CG strokes at 150 az at 20:55Z.
20:58 Second RHI in this 10 min series is centered on 150 to look at near convection (as well as different portion of far (80-120km) stratiform area).
21:10 Started dd on west lobe (far) scanning w TOGA. RHI centered on 272, sector centered on 120.
21:20 Main cell in W dd lobe at 278, ~ 50km. RHI’s in prior scan show nice bright band and some stronger (40 dBZ) echo at 6km height. Above the cores in the lobe is a large anvil region, from prior storms and current storm. Cloud tops above convective core to at least 14km.
21:26 Next RHI’s centered at 270 (264-275).
21:34 Still on W lobe dd scans, third round. Next RHI centered on 267.
21:40 Fourth dd in W lobe. New cells forming, as older cells falling out. Current Cell on last RHI’s (262, range 43 km) has ZH to 55+ dBZ, good phi-dp shift also. New RHI centered on 266 (260-271).
21:55 Now on fifth w lobe dd sector. Just barely topping in fourth and fifth sector scans.
22:01 Sixth dd sector. Cells are beginning to weaken (Peak Zh at 40 dBZ).
22:10 RHI’s from last sequence loop at incorrect position (291-301). Started 10 tilt 360 Surv. Scans since was topping decaying cells in W lobe at 11.
22:40 10-Tilt 360’s cover all cells in range. Still some cells in W dd lobe, none over 40 dBZ now.
23:55 Cells have continued in W dd lobe at low intensity and always topped by 10-Tilt 350 sweeps. Additionally convection to SSE at 100km range, with moderately strong echoes (40 dBZ+). Cells are all propagating from E to W.
February 11, 1999
00:55 Scattered Convection. Cells still propagating E to W, with very small southerly component. No cells currently exceed 40 dBZ. One cell of 40 dBZ at 289 107km. One complex with 40 dBZ centered at 200 range of 90-120km. Smaller cells to N and E of TOGA. Weaker cells (20-25 dBZ) NE of SPOL at 100km, and S of SPOL at 25-30km.
01:10 Resynched so 10-Tilt 360’s start on the 10’s. It was some 20 seconds off.
02:05 360’s Tilts are running fine. Scattered convection is all to the East, from South to North, all over 100km distant, no strong echoes all below 20 dBZ.
02:58 Nothing out there, still running 10-Tilt 360’s.
06:35 Was clear enough to see the large magellenic(?) cloud, but a thickening deck is moving over us.
11:34 Small band of ‘showers’ seen to the NE, outside the rain can be seen in the distance.
12:05 running vertically pointing scan. Light rain outside SPOL.
12:12 It looks like a good mean and std. Deviation.
12:13 Restarted survey 2 (10-tilt 360’s).
12:14 2 Distinct bird bursts this AM. Did someone say ornithology study??
12:30 Started a scan over the #1 rain gauge and profiler site. May be some light precip near the gauges.
12:38 If we are lucky there might be light drizzle over the profiler. The are 20 dBZ echoes in the area.
13:20 Going back to 10-Tilt 360’s.
14:40 Trmm2.scn started to cover rain over #2 and #3 rain gauges.
14:53 Cells 120km to the WNW and 140km to N. (40 dBZ max).
15:00 10-Tilt 360’s up to 10.5 with some RHI’s thrown in. Precip. Has moved west of the rain gauges.
15:10 Antenna must be halted for ~ 5 minutes. RHI’s must now reach the proper azimuth before ramping up in elevation. (Jon Lutz’s fix).
15:14 Began survey again- will cut off RHI’s to resynch on 1520.
15:17 Storm 130km to the north is vigorous as evidenced by RHI’s. Tops are still only 12km or so, but increasing.
15:21 Resynching gradually, so as not to cut off previous volume scan. Some cells are fairly close and would be nice to top. (25km across NE quadrant).
15:26 Distant Northern cell is ~ 14km high now.
15:31 10 Tilt 360’s began (one minute late).
15:38 Now cells in eastern dd lobe. (new ones).
15:50 TOGA says their dd lobe is much smaller than ours. The cells I see are in the e dd lobe, but according to TOGA they are not.
16:00 Hi res scans on w dd lobe (trmm6.scn). Cells are very new here and hopefully will develop more. They are and they are proliferating. Good convective initiation study.
16:22 Asked TOGA to shift their sector counter-clockwise a bit to capture cells near SPOL.
We are not regularly scanning a few major areas of convection One to the NNE by 80-100km and to the SSW by 80km. Both clusters appear to be on the verge of organizing into a bigger system. Perhaps with shear aloft, they will.
17:09 Doing RHI scan (slow rate) for phi-dp cal centered at 206, 102km in range. Elevation a tad to high will repeat with center at 208.
17:20 Will switch to convection near profiler at 17:30, doing Hi-resolution scans. Old cell is fading a little (one to the west). Excellent lifecycle study. Almost to the bitter end. Still more devt. Potentially.
17:19 Did another ppi scan at 208 azimuth.
17:40 Doing hi res over convection near profiler.
17:50 Did a couple of RHI’s over profiler. Changed elevation angles to encompass more of the storm. Remaining on 90 sectors every 4 minutes and 2 minute 360 surv/ RHIs.
18:01 Cells merged into line and have started to form a trailing stratiform area. Well see if the environmental shear is strong enough to keep it maintained and not let it fizzle out before it hits the airport/profiler site.
This is a good high time resolution dual-Doppler case covering the merger into a mature squall line from more separated beginning cells. Lots of High resolution scans (2 complete volumes every 10 minutes).
18:09 Radar scanning sequence has been: 4 min 90 sector (topping storms adequately)
4min 90 sector (topping)
1.5 min. 360 surv. At 1.1 el.
0.5 min. RHI’s over profiler.
18:22 Heavy rain gradient very near profiler. But they might not be in the heavy rain yet.
18:24 60° phase shift along squall line.
Cells should be electrically active and flat plate should register them. All afternoon, outside observers have heard thunder and/or seen lightning nearby.
18:38 Another psi test through line (0.05° /sec). scan rate is very slow, in RHI mode. Asked for 256 samples (widening beam a little).
18:48 Potentially good calibration with SPOL and TOGA. RHI’s taken along baseline simultaneously. Made hard printouts to compare back in Ji Parana.
18:51 Good trailing stratiform now forming. High psi shift. ~ 95° through line.
18:58 Got good RHI through leading convection its not very tall until you go rearward. In other words, its tilted rearward.
Will do psi test (256 samples) 0.05° /sec scan rate at 1908 through line. At 311 az.
19:10:15 Began 90 sectors again.
19:40 Squall line’s weakening. Back in 1830 TOGA had to switch out of 90 sectors since the line was on top of them. Now some puffy clouds are in the western DD lobe on the southern end of the line. They are not too strong however.
20:12 Continuing 90 sector on squall line in Northern portion of western lobe. Tried to call TOGA to check on their status, unsuccessful.
20:30 Called TOGA starting coordinated 90 hires scans (2 sectors + 2 tilt 360 surv. In ten min). Small strong storm (not scanning w/ sectors) at 125 az. And 35km. Cells at 21, 49, 61 all > 100 km. Also at 227, 195, 178 110km. Cell motion is towards the SE.
20:50 Resynched start of 90 sectors. Squall line continues to decay, although furthest cell is still active, but is at edge of Doppler lobe (280, 110km).
21:08 Squall is now just a cluster of cells (278, 113km) Cells in NW portion of E dd lobe, may be worth turning to as old squall line is leaving range.
21:15 Still on Hi time resolution 90’s on old squall line (278, 117km).
21:37 Stopped 90 sectors early and running 2 tilt 360. Going to start 10-tilt 360 to cover entire area as storms are all far away now (> 90 km).
21:40 Started 10 Tilt-360 scans. Line in E lobe has good strong echo (55 dBZ, Zdr to 4dB). Shift to sector, can’t reach TOGA. RHI’s are really nice showing 40 dBZ to 15km !!
22:00 Started 2 90 sector (centered at 51) and surveillance (2 tilt) on storm. Very strong elevated cores in upper portions of storm especially in early RHI’s (2155).
22:20 Still doing 2 90 sectors on storm in E lobe, still strong, strong echoes not as high as 21:55
22:30 Storm (45, 55-70 km for convective cores at 1.5 el.) still has two cores stronger than 50 dBZ.
22:48 Storm heading for profiler site. Stopped second 90 sector on this ten minute cycle to get surv. Early.
22:50 Tried rain gauge scans, but storm not on site yet.
22:53 360’s to cover area
22:55 Ran far 120 on wrong center then correct at 22:56
23:02 Ran 360, and now 90 sector at 40. Going to switch to profiler scans to cover area as storm hits it next. Can’t reach TOGA for last 15 minutes.
23:06:26 Stopped 90 after 15.8 el. And started rain gauge #1 and profiler scans (trmm5.scn), stay with these as storm continues over site.
23:29 Continuing to do scans as in trmm5.scn. Storm reached profiler site as it was decaying and continues to break up. Was at least 40 dBZ near/at profiler when it first reached but quickly weakened.
23:45 As this storm died a storm, which moved in from the east has been producing large amounts of lightning so was the storm which reached the profiler with visual flash rates approaching 1 per second at times (usually less, like 1/ 5 seconds), of course the lightning ceased some time after 23Z.
Now only low reflectivities left near profiler (< 25 dBZ). Will switch to 360’s at 00Z.
23:50 Storm to NW and E still producing lighting flash rates ease up some.
23:57 Running 360 surv. 2 tilt early, going to run another 10 minute rain gauge #1/profiler loop since still some 25+ dBZ over last rain gauge.
February 12, 1999
00:00 Start another profiler/rain 10 min loop.
00:10:11 Started 360 10 Tilt, reflectivities had just dropped off at cell rain gauge sites.
01:17 Everything died in place over the last hour.
02:16 All quiet
03:59 Lightning seen due east several strokes per minute for a while cells approaching from the east with reflectivities as high as 45-50 dBZ.
05:16 Large cell(s) to the southeast moving to the southwest
06:02 Large strong cells to the SE, reflectivities between 55 and 60. Tops near 15? Km from Rd display
07:32 Gust front from cells to the southeast seen we should see it here soon.
13:10 Running 10-tilt 360’s. No activity whatsoever Just a bunch of bugs!
14:17 10-tilt 360’s.
14:30 Starting to see enhanced echoes near TOGA. Just to SW and a little farther to the NE. Zh ~ 40 dBZ (peak) near ground.
14:41 The east dd lobe has small areas of enhanced reflectivity at around 80 km. These developing from several lines of clouds, that are somewhat aligned with the ridges in the eastern (and to the east) of lobe
15:17 The lines of clouds in the eastern lobe have disappeared from view. Kind of dissipated. I guess. A few areas of heavy rain have developed. One to the south by 80km. One near TOGA and one 60 km to the east.
15:26 40 dBZ to 8km AGL in east cell about 60km range.
15:30 Began 90° sector (high time resolution) centered on 40° azimuth. Eastern cells grew rapidly in last 10 min. TOGA down for past hour or so. They are calibrating it or something. May be down for another 20 minutes.
15:45 Eastern cells appear very vigorous.
15:49 RHI’s through E cells.
15:51 Started 90° sector 1 min. late. But that doesn’t matter with no TOGA!
15:56 Its gust front appears to be surging eastward.
16:01 Good Zdr, ldr columns evident in RHI’s. Shrunk sector to 80° . Not cutting off anything. Don’t worry.
16:11 Running out of time in 10 minute periods, so I shrunk the sectors to 75° . Still capturing the entire complex.
16:30 TOGA is up! Doing hi res scans with us on the same cell. Both planes are flying today. Should have ER-2 by 17:35 (by radio)
16:48 Eastern complex is bigger but less vigorous, probably.
16:50 continuing w/ 85° sectors. The best part of the cell is moving outside of the lobe. We’re missing some of the stratiform anvil off to the NW of the cells too.
16:59 started 360’s. Cut off 0.7 ° one.
17:00 Began hi res sectors. Will do vertically pointing, perhaps?
17:09 Vertically pointing scan begun. Didn’t get it. Will try again.
17:19:37 Vert. Point. Yes.
17:20 Starting flat plate program. Heard thunder.
17:24 Started 90 ° sector again. Missed one all together.
17:29 Started 90 ° sector again.
17:37 We’ve had heavy rain, southeasterly blowing gust front, and lightning at S-pol.
17:50 Will move back to 10 minute resolution. Doing 120 ° sector scans centered on 120 ° azimuth up to 31 ° elevation.
18:00 TOGA is going to near 360’s out of hi res scans. Citation has made contact and is on its way.
18:02 Widening sector to 135° .
18:06 RHI through TOGA
18:14 Needed to interrupt for air support RHI.
18:16 Started 135 ° sector from scratch again.
18:18 More air support RHI’s
18:20 restarted 135 ° sector.
18:38 TOGA RHI (through 323 ° azimuth—the radar baseline)
18:50 continuing 135° sectors. With air support RHI’s thrown in.
19:09 TOGA RHI
19:10 one more volume to the south then switch to hi res on cell to the NE.
19:24 TOGA is coordinated on the 10’s.
19:28 Profiler RHI’s (23 and 24° azimuth)
19:37 Profiler RHI’s (23 and 24° azimuth)
19:44 Jon Beaver took a picture to the NNE.
19:51 Still running manual sequence of 2 90° sectors until topping storm at 17° . then RHI’s over profiler (22-25° ) Finally a 1.1° 360° surv.
20:01 same pattern, stopping sectors after 19° scan (just topping) We are synched hi res with TOGA.
20:02 Changed center of second 90° sector from 16 to 13 ° az. RHI’s from 20 to 23 ° az.
20:10:23 Started 23 seconds slow since last sectors had to go to 21 ° to top. Since this storm is still approaching radar. Citation reported frozen drops and graupel in earlier passes.
20:20 46 seconds slow. Going to have to drop some high scans on second sector, also dropped 2 RHI’s, only did 22 ° and 23 ° in last sequence. Also changed width to 80 ° on second sector.
20:30 11 seconds behind. Last double next 10 will be single 135 ° sector.
20:40 135 ° dd E lobe centered on 45° , started 3 seconds off.
20:50 Added two elevations to sector (17.5 and 19° ) This sector covers storm immediately E of radar which is being flown now. RHI’s (346-348 & 74-77)
21:00 last 10 minute had extra 40 seconds or so. Added more RHI’s to list (345-348 & 72-77)
21:20 Did continue to do 135 ° sector centered now at 41 ° (to catch cell hitting rain gauges #2 #3 #4). Add RHI’s over gauges.
21:40 As storms die, now switching to 360’s, 10 tilt.
23:03 Still some distant convection moving E-W to NNE and SSE of radar. 10 tilt 360’s running.
February 13, 1999
00:30 Started modified 360 surv. With RHI’s in case cells to NW hit outer rain gauges. RHI’s at (331-332, 343-345) for this 10.
03:41 Continued with pattern as before with surv. And RHI’s as cells continued near rain gauges.
03:50 Back to 10 tilt 360’s.
04:05 Taught myself how to use the antenna controls with help from Jesse RWP
04:10 Started back on trmm4 survey scan
06:10 Restarted at the top of the hour
09:30 Very heavy dew or very light drizzle. Hard to tell because of sky conditions.
14:37 Citation 1630 take off time. 1730 arrival.
The plan of attack is to sample growing turrets. We will direct them to them. And they will fly near –3 C in the best ones.
14:50 Getting scans back on the 10’s
15:00 Initial tiny cells have sprung up 120+ km to the NE and 60 km to the SW.
15:30 Widespread puffy clouds are evident on radar. Some have precipitation forming in the NE quadrant.
16:15 The NE hemisphere is rapidly filling with echoes. Very high concentration of low towers now. Top around 5km.
16:17 The citation would love to be outside now. Growing turrets are everywhere.
17:07 Called TOGA. Switching to hi res scans over e. lobe.
17:10 Started 90 sectors in e. lobe. 2 updates every 10 min.
17:24 RHI’s through cell plane is going through.
17:37 TOGA is going on 135 sectors just catching the cell 30 km to their north which the plane is working and the profiler site.
17:41 Cut off sector to recenter to the left further.
17:49 Did RHI’s "near" plane location
17:55 Profiler is close to heavy rain.
17:57 Haven’t done the tops of the storms near the profiler, but better vertical resolution is important in the vicinity of the aircraft.
18:08 Will do RHI’s over the profiler.
Telling TOGA to focus on profiler. They don’t have to change much.
18:18 More profiler RHI’s
18:28 More profiler RHI’s
Citation is working about 20 km in advance of Solid t-storm line south of profiler.
18:26 -4 pass just completed
-6 pass about to begin in the citation
18:30 Last pass saw columns and small rimed graupel outside citation. The cell abuts the large mass of precip. But no ice is falling into it from above.
18:34 RHI’s were not topping over profiler So I adjusted accordingly.
18:40 TOGA is switching to near 360’s since precip is so widespread and nearby. Citation moving westward close to the radar base line.
18:47 Citation is running out of fuel and is heading back after flying over profiler at 25,000 ft.
18:55 Lots of ice types and a little bounce in the Citation.
18:58 RHI’s over profiler will be very good (2° . /sec) Plane just flew over the profiler. I cut the sector volume short to begin the RHI’s.
19:00 Will probably move to (10 minute) sector scans ? Since Citation is flying home?
19:04 Will try a slow psi shift test. (to calibrate Kdp).
19:28 Will try a slow psi shift test. (to calibrate Kdp).
19:27 Audible thunder in seatainer. Saw a couple blips on flatplate graphics.
19:37 Did 135 sector toward SW. Adding RHI’s to top it.
19:56 Since there’s no hope of getting this topped with Volumes I’m doing many RHI’s
20:04 Doing far polsec scan on area to the S/SW of SPOL. Along NW to SE line has moved through.
20:12 RHI centered at 230 (WRITING DIFFICULT TO READ 236 perhaps)
20:14 Not synched up well on the polsec scan will reset at 20:20
20:17 It looks like another line is growing and approaching the profiler site. Will keep an eye on this.
20:20 Resynched pol sec far scan
20:50 Continuing the Pol sec scan. Very good storm to the SW. Best I’ve seen. 18 km tops, Zh ~ 60 dBZ in a core, Zdr column is well defined, with LDR cap. Ldr ~ -18 dB at top of Zdr column.
21:13 RHI’s at around this time are centered incorrectly. I was showing scan sets and the table changed.
21:31 RHI’s centered on large cell that developed probably from outflow of storm described (at 20:50). Zh peaks at 50-55 dBZ, Zdr close to 3.5 dB. Cell is 110 km out at 210.
21:36 The line to the NE, above the profiler site looks to be diminishing. Turning into a large area of stratiform type precip.
21:49 Will shift to 135 sectors on the east lobe to cover the stratiform rain, as it closes in on the profiler site. Past experience says it won’t make it but we will see. The main core of the cell to the SW is 120 km and moving away.
22:01 Starting the trmm6 (meso far dd e)scan centered at 24, with an RHI centered at 22. This covers a large stratiform region in the E lobe.
22:02 The #3 fixed angle table was missing had to reinstall RHI angles
23:30 The stratiform area quickly died off before reaching the profiler site and the rain gauges. Going to 10-tilt 360’s for coverage. Coverage area is starting to clear out. With some stratiform rain in the SW and some convective cells at the edge of the w dd lobe (moving away).
February 14, 1999
00:27 Started rain gauge loop. A convective cell to the NW is covering the #4 rain gauge site. Zh values are around 30-35 dBZ, with 2 dB Zdr’s. Visually we were seeing lightning come from the cell. Most all activity is diminishing. This looks to be remnants from the NW to SE line that was in the area earlier.
00:40 Resynched rain gauge loop. Still 35 dBZ over site (#4) but cell seems to be losing strength as well as moving to the SW. this is a small cell so it probably won’t cover site for long.
01:17 Cell has moved off of #4 rain gauge site at 20 past, going back to 10-tilt 360’s.
03:13 Continuing 10-tilt 360’s.
04:00 Resynched 10-tilt 360’s.
09:55 Didn’t notice (since I was looking at low level loop) but an area of weak echo has moved (< 20 dBZ) into the 100 – 120 km range E to NE of the radar. Otherwise it has been quiet all night. Fog was thicker earlier (0700), but now you can see up to a high patchy cloud deck. Looking back at the scans the echo moved in from the E around 0800. Actually patchy echo on most upper level scans (2.3 to 8° ) generally to NE and E of radar and never strong (< 20 dBZ) Resynching 360’s for next 10.
11:24 Nice circular burst centered around 12 az range 40.5 km, just N of downtown Ji-Parana! From 10:20-11:00 on 1.1 el. Scans. Peak Zh of 20 dBZ! Speed of expansion, 45 km/h . No phase shifts, believable velocities and Zdr’s of –2 dB to 3 dB. Strange birds.
12:09 10-tilt 360’s
14:26 10-tilt 360’s. Both the ER2 and Citation will be flying today. at approximately 1730, they will be in the area.
14:29 Not much out there at the moment.
15:19 Seeing pockets of convection to the west at about 120 km and some development to the NW at 120 km.
15:45 Western part of coverage area is becoming more clustered with small pockets of convection. Particularly to the N. Directly west, the earlier areas of small convection are building now.
16:20 Running RHI (centered at 29° ) through a cell in the W dd lobe. Cloud tops 9-10km Peak Zh ~50 dBZ, Zdr peaks 2.5-3 dB. Cell is in blockage area about 65 km to the NW of SPOL (295° )
16:30 Some new growth just to the E of SPOL at 40 km and further E at 110km. Development in the W dd lobe is forming an E-W line. Cells to the S are intensifying (128 km away). And there looks to be potential for growth in the east dd lobe, in the usual area NE of Profiler site.
16:39 Running an RHI through the cell to our E, to get a better look at what it is like.
16:47 Running RHI through cell further to the east @ 104 km, centered on 97° .
17:14 Planes are due in the area at approx. 1730.
17:26 there are 4 isolated cells just to the E of SPOL starting at 18 km out.
17:40 ER2 has made radio contact and possible start working area at 1810.
17:47 ER2 will do a 60 km line to the E of SPOL along a line of activity running from SE to NW. Will start 135 ° sectors at 50 past.
17:49 Citation has made contact. 231 km out.
17:50 Started the 135 ° sector scans on the dd E lobe. TOGA will synch up with us at the top of the hour.
17:55 15 ° seems to be topping most of the stuff. May need to switch to dd near.
18:00 Line has 14 km tops. Zh peak 40-45 dBZ, Zdr’s ~2.5-3 dB near Zh peak. The line is now centered at 72 km, 103° .
18:05 Still pretty much topping everything even the stuff close to us.
18:11 The Citation will be working the same area as ER2. Citation at 25k feet.
18:24 The planes are still working the line to SPOL SE. We are still in 135 ° sector scans synched with TOGA.
18:29 In next 10 min. or so the planes may move to activity in the dd e lobe. Very dry. Shear very weak
18:40 Started high res scans with center at 45° .
18:50 TOGA will be synching up with high res scans.
18:57 The planes are flying N-S line just to the NE of the profiler area.
19:01 Small graupel 1-2 mm, small particles at 27k is Citations report, Along line. 12-15 km tops, Zhà 45 dBZ, Zdrà 3dB peaks
19:08 At 29k ft., Citation sees 1-2 mm graupel. Cloud tops are 15 km.
19:09 Still doing high res scans with RHI’s added at the end of the sequence.
19:10 Shifted sector center to 40° ., with center of line at 75.2 km.
19:29 10 km larger particles on cloud edge with small particles in the middle was report from Citation.
19:38 Citation lost cabin pressure and is heading back to Porto Velho
19:47 At 50 past, TOGA will be switching to its 150 ° sector scans still 4 min updates.
19:50 Resynched hi-res scans.
20:15 Started hi res scan 30 sec. after the 10’s.
20:43 Started survey loops ER2 goes home.
20:58 Start baseline RHI for comparisons.
21:00 Started survey loop
21:40:40 Start RHI sector along 300-310 ° storm has a deep mesocyclone and large shears.
21:50 Restarted surveys
22:36 Sector RHI’s along 195-220 for a storm just entering DD lobe
22:50 restarted survey loop looking for a DD to do.
February 15, 1999
01:00 Started a loop survey RHI on two cells to the E that have a lot of lightning in them. A long thin line of storms approaching from . hope they last long enough to do a dual-Doppler.
01:50:12 started a 90 ° sector dual-Doppler on a line storms entering the DD E lobe surveillance scans will be a little late.
03:27 Shifted over to the profiler scan to cover the profiler as the line passes over it.
03:45 Running trmm5.scn "Airport gauges" Heavy rain over airport.
04:20 TOGA switched to near 360° ’s due to proximity of line.
04:30 Switching to "all rain gauge" scan. (trmm7.scn)
04:47 Squall line is not as sharp now. Before it was much narrower. Now it has spread out all over. 60 km to the NE, behind the convective line, intense rain redeveloped. Thunder audible in the seatainer.
04:51 Intense redevelopment in E-W line perpendicular to squall line 60 km to the N of radar. Very interesting.
04:55 Rain gauge networks #1 and #2 are getting hit hard. But #3 and #4 are also getting some rain.
05:03 The main convective line has weakened but an arc of high Zh (> 45 dBZ) has formed 25 km NE of the Ji-P airport. Kind of unusual to see such strong redevelopment in a region that was just subject to an intense convective line.
05:15 RHI through 30° .
05:20 RHI’s reveal (in convective regions) low Zdr just at about the 5 km AGL level bounded by higher values above and below. I understand what makes it higher below (oblate liquid raindrops), but above, I wouldn’t expect a bunch of non-zero Zdr’s. In the updraft it is zero, indicating graupel, but in the other regions it is 0-0.5 dB indicating horizontally oriented ice crystals (???). Differential phase shift is also at a minimum just above the melting level and greater within some of the frozen precipitation.
05:40 Did slow scan (0.01 ° /sec) with 512 samples through large differential phase shift azimuth.
06:33 Getting lots of rain over airport. Adding RHI’s to cover #1 rain gauges.
06:50 According to the Kdp estimator of rain rate, the #1 rain gauge site has had b/t 10 and 20 mm of rain over the past 2 or 3 hours. This is an excellent opportunity to intercompare different polarimetric estimates of rain rate. In fact, the other polarimetric estimators (e.g. Zdr, hybrid, etc.) estimated b/t 15 and 25 mm accumulation, while the Z-R estimator was much lower (12-16 mm).
06:55 I considered switching to a 360 ° volume scan, but since all four rain gauge sites are receiving light to heavy rain, I kept the rain gauge scans running with RHI’s over all the #1 sites (and the profiler). #1 continues to receive heavy rain.
07:09 The arc has a bow echo-like appearance. It is intercepting a narrower N-S oriented line of enhanced reflectivity which is currently passing over S-pol. the narrow line is wavy on the scale of 5-10 km.
07:17 Airport appears to be out of the rain now. I will switch to trmm2.scn (for rain gauge site #2, 3, and 4).
07:25 Will add RHI’s along the baseline since it is covered by stratiform precip. Now. May be as uniform as we will get.
Made color prints of baseline RHI’s for 07:31:38
08:18:02* * good timing with TOGA
08:20 Rain is finally exiting some of the rain gauge sites.
08:35 Began hi res scans on E dd lobe for some "newish" convection.
08:40 Decided to just run 360 ° ten-tilt surv. Scans. It’s not that intense of a storm in the E dd lobe.
10:20 Good bird burst from near Ji-Parana.
10:48 Complex in E dd lobe is moving over rain gauge #3 now. It’s got moderate rain with reflectivity maxing at around 35 dBZ.
11:44 It’s gray outside. DD lobes are clear of deep convection. Possible new complex appearing to the ESE that looks more intense than the precipitation just now exiting the dd lobes, moving westward.
12:26 Complex to ESE has three embedded cells with reflectivity peaks between (35-40+ dBZ), and the echo has approached within 80 km of SPOL. It is below the E lobe and looks to be on a track to miss most of the dd W lobe. Has top at 119km to 11km AGL. Being topped by 4.7° . , so will remain with 360’s for the time being.
12:40 Storm more intense on southern side, won’t go near rain gauges, probably will completely miss W dd lobe on the south, redeveloping cells in the complex are on south side. Resynched 360’s on this ten.
12:58 Complex to ESE has weakened but continues to go west. Going to do dual 90 sectors and 2 Tilt 360’s.
14:11 Running 2 90° . sectors and 4 Tilt 360 surv. (.7, 1.1, 2.3, 4.7).
14:19 Storm dying so stopping sectors and going back to 10-Tilt 360 surv.
15:17 Things are very quiet, the complex is nothing but a smidgen of debris. Still 10-tilt 360 surv.
16:52 Until recently nothing was happening. A small collection of turrets have formed on some higher terrain growing from 5 km (AGL) tall about 10 minutes ago to about 8km AGL with 40+ dBZ peak Zh’s. They are at about 200° . az. And 110km.
17:26 Besides slightly organized bunch of cells mentioned previously, popcorn convection starting in some spots. Group of cells to SSW are showing signs of movement to the SW which would take them out of range.
17:42 A cluster of cells to the farthest E range is beginning to move in. It also has an upper level low level refl. Area, anvil. There are about three small (< 5 km AGL) cells in the E dd lobe, in addition to the complex to the south at az. 210 and distance of 100-115 km.
17:56 Cells growing. Rainshaft visible very close to here at SPOL. Switching to 135 sector on e lobe and shifted to a center of 38° . az to catch complex to E. Can’t reach TOGA presently.
18:12 Another 135 Sector on E dd lobe centered at 52 az. Last RHI’s (18:00) were at (71-73, 100-104) New RHI’s at (72-75,104-110). Called TOGA, told plan to both scan E lobe, they mad do 4min x 2 sectors but I’m sticking to 135x 1 to catch complex to the east.
18:29 Good cell next to radar, thunder heard just before flatplate turned on. Several close loud flashes . Manually running RHIs first into storm nearby, didn’t top at 30° ., going to try 50 ° el.
Did many RHI’s finally topped by doing 70° . el. (az. 298-302). Did 2-tilt 360 surv.
18:50 1) Meso dd (far) E lobe 135 on 52
19:01 1) Meso dd (far) E lobe 135 on 52
19:10 1) Meso dd far E lobe 135 on 52
19:20 Started 90° . sectors dd hires on E lobe, to concentrate on the organization of the cells into lines. (trmm6) with 2 x 90° . sectors (of the first two 90’s the first was centered on 38, the next on 41). Then 2 Tilt (0.7,1.1) 360 surv.
Line stretches to east over 100 km long! Not extremely high dBZ (40-50 dBZ peaks), but phi-dp indicates most cells are raining heavily.
N edge of this line is entering the E edge of E lobe, while two small cell complexes are ahead of the large line. May begin to lose tops of some cells in SW corner of E dd lobe in sectors, but not going to bother to top at present.
19:30 Continued 90’s in E lobe.
20:00 Strong cell near the profiler. Started trmm5 to catch the storm over the rain gauge net.
20:15 Started a meso dd 325 to 100. Heavy rain at site. Lightning strokes recorded on the flat plate.
21:10:08 Reset DD sector to 360 135 sector.
22:30 Storms have petered out call TOGA and told them we were shifting to surveillance scans.
February 16, 1999
04:14 Going to resynch surv. Scans, nothing out there but cows and fog.
08:44 Weak echoes to SW at 100+ km range.
10:22 Another good bird signature, also some cells to 8 km AGL to NNE at 120+ km.
11:25 Cells to NNE have continued to propagate to the SW and now have some tops to 12 km AGL. Peak reflectivities in the cells is already at 40-50 dBZ, with phase shift indicating some significant precipitation. These cells are located just beyond the N edge of the E DD lobe and on the current track will hit the furthest gauge network in an hour or so. Resynched surv. Scans on 1140.
12:42 Growing mass of cells 90-160 km out. Situated just NE of rain gauge site #4. Might start rain gauge scans soon if #4 site gets hit.
Thought about switching to rain gauge scans (#2 #3 #4) because #4 is intercepting some light-moderate showers soon, however, the rain never arrived in sufficient quantities to warrant a switch.
13:34 Isolated cell popped up recently 10 km S of TOGA. Top of ~6 km.
13:55 Mass of precipitation to the NNW is extensive but is outside of rain gauge network and DD lobes.
13:58 RHI’s thrown in for isolated cell. Cell tops to 8 km.
14:09 Some more RHI’s through cell near baseline. Tops only 6.1 km.
14:22 Called TOGA and suggested moving to 90 ° sectors with hi-res in western lobe to capture convection beginning to pop. But Ziad suggested waiting, due to the much stronger system that’s being scanned to the NW by 100+ km. Fair enough.
14:30 Began hi res scans centered on 315° . This will cover everything for us.
15:00 Adapted hi res scans to wider sector (~100° ) and fewer elevation angles since all storms are being topped early. This grabs a couple new cells to the W.
15:17 I noted a lot of dragonflies about outside. They love those puddles. These insects have a very large Zdr, and we’ve seen some signs of this in the boundary layer, and in the outsides of precipitating cells (bugs sucked upwards in wind?? Possibly.)
15:40 Convection has been weakening and moving further to the W. Nothing else has developed, so I’m continuing the sector scans (90 ° now). The scan rate has been slowed to ~5.2 ° /sec in an effort to improve spatial resolution. We have the extra seconds to do so, since we have no need to include high elevation angles.
16:12 Began 360 ° surveillance’s. Because isolated cell just popped in E DD lobe.
16:14 Storm that is still sliding off to the W is looking stronger in the low levels (high Zh, good convergence) but it is moving out of the DD lobe. (13 km tops) Packet of new cells 50 km to the NNE looks promising however.
16:19 RHI’s over profiler, near new cells.
16:29 RHI’s over profiler, near new cells.
16:40 Cells appear too dinky to warrant a special run of trmm5.scn.
16:59 Some taller cells 15 km to the N appear solid on radar in a narrow column, but look ragged on the edges when you see them visually. Could be fighting dry air.
17:24 Strong complex is moving into eastern quadrant. Still is 160 km out. Other cells in vicinity only reach ~5 km.
17:47-17:52 I have an RHI sequence that is very interesting when looped. Just 5 km cells along an azimuth approximately parallel to the direction of propagation. The time resolution is high (new frame every 18 seconds). Shows growth and settling of blobs of precipitation very nicely.
18:13 The cells within 100 km still are shallow with 5-6 km tops. But the approaching squall line in the E is quite deep.
18:17 Perhaps the forecast for dry air is squelching moist convection over the radar region currently, but the squall lines probably initiated much to the east, perhaps in unstable atmosphere more favorable for deep convection. Will it run into the dry air and evaporate? Only time will tell.
18:40 The strong line to the E has maintained its strength. The trend is steady. Its anvil is being blown in front of it by a ways and is starting to be missed by the 360 ° surv. Scans. May switch to a sector scan with more elevation soon.
18:50 Started 150 ° sector centered on 65 ° with 3 RHI’s and 2 tilt 360’s included. This encompasses all the main convection moving this way—at least for now.
19:17 Running trmm5.scn to cover airport getting grazed by heavy shower.
19:30 Want to switch back to sector scans to keep captured the approaching and consolidating squall line.
19:36 Fairly brisk ~3 m/s NNW wind feeding into approaching line. Solid tops to 16 km AGL.
19:50 Upon prompting from TOGA, we’re switching to hi res stuff over S part of E DD lobe.
19:53-19:56 Had to stop recording data briefly because the DORADE recorder died. Missed upper-elevation angle scans of 1st hi res volume and all of 2nd hi res volume.
Data possibly may not have been lost. The techs aren’t sure if it was "cached" or not.
20:42 Started an RHI sector along 118-120 ° . Will restart the DD on the 10’s.
20:50 Started a sequence of meso-dd e loops but halting 2 minutes before the end of 10. The getting only a 1.1 ° scan, doing an RHI along 120 ° and then starting a meso – dd-e loop nice bright band in the Rhi scans
23:30 Stopped sector scanning and changed to hi res DD JA in SW quad with some RHI’s.
23:40 Started a 10 min. 90° sector, 10 azimuth RHI 2 tilt 360 in SW lobe.
February 17, 1999
01:30 Started survey scans.
07:38 Still largely clear.
10:56 continued surveys.
11:54 A few dinky cells in the western DD lobe, but nothing to write home about.
12:07 Radar data collection stopped to do a solar calibration.
13:13 Started 10-tilt 360 after Jon Lutz completed solar calibration.
14:04 Nothing much out there, still in surv. 360 mode. Talked to project house, 2 plane day, ER2 scheduled for 16Z takeoff and Citation for 17:30 Z takeoff.
14:10 Synched scans to the 10’s
15:12 Some cells in NNE beginning to form, moving to SW. Tops to at least 6 km AGL now. Otherwise clear.
16:10 A bunch of visitors came through. Cells are beginning to intensify to the N. The ER2 took off and is en route.
16:30 Started dd in E lobe. Hi res 2 x 90 ° sectors. Centered on 15 (1st 90) and 18 (2nd 90), 360 surv. Afterwards. Couldn’t reach TOGA.
16:50 Cells at 20 to 50 km around 40 ° az in E lobe has grown to tops of at least 13 km AGL. Can’t reach TOGA still to start sectors between us, perhaps they are doing E lobe perhaps not.
17:07 RHI’s into close system, and one right over profiler.
17:14 Last sector didn’t top close storm at 15. ° el. Switching to trmm1.
17:22 Top of system at least 15 km AGL , also ran more RHI’s over profiler. TOGA just started sectors with us, their desk phone is down.
17:40 Still running 1 x 90 ° sector to top close storm. Over profiler and to our NE (close range). Other games in town, but none in lobes but this.
17:45 ER2 to arrive in 22 min, going to fly on cells in E lobe. Cells close are linking up in a line to the NNE with more distant cells. This corresponds to topography of ridge just to E of river.
17:55 ER2 coming in from E and running on our line of cells. Citation also en route to arrive in area soon.
18:04 Going to switch to far scanning and not catch tops on close storm, as interesting associated conv. Through- out E lobe. (trmm6).
18:13 New 135 sector, to 15.8 el, won’t top close things.
18:32 Last RHI’s missed good line by some. A secondary line has formed E-W across N-W line, and has even begun to dominate. Strongest cells at junction.
18:40 Rain and frequent lightning. Flatplate rain signal 18:38à ?
18:48 Still raining here. But scans concentrating on line out to N.
19:13 Still on 135 sector on complex to WWW (center), previous system which ran over us is by. Still very strong 16+ km AGL tops.
19:34 Complex has begun to weaken, some broad areas of echo exist in E lobe. Citation leaves area soon.
19:39 TOGA called still scanning E dd lobe. Citation doing a spiral descent around 0 ° az from us in the complex in the E lobe.
19:48 Some RHI’s to growing cells to S. Good intense high tops as opposed to decaying system to N.
19:58 Ran RHI’s S and 246-256.
20:01 Stopping sector for 360’s, while decide where to send ER2 (Citation finished spiral descent and left for home.)
20:13 Started 120 sector centered on 180. RHI’s centered on 187, since ER2 is flying this storm. No more coord. with TOGA. Can’t reach TOGA by phone.
20:30 Shifted RHI sectors to 190-202.
February 18, 1999
03:51 Leading edge of squall line bisects the radar scope from N to S. Behind the convective line is dense stratiform precipitation. Isolated hvy. Showers have popped up over TOGA and in western DD lobe. Gust front is running ahead of convection but it constantly spawning new towers. System is so widespread that any sector would cut much of it off. This may be best captured in 360 ° surv. As it has been since its inception. At least, I assume that’s what was running before I got here.
04:00:25 Old 10 min. cycle was running too long, so resynched on the 10’s. Also dropped RHI’s for now and added two tilts to the elevation angles (Survey 2 in trmm4.scn)
04:12 Heavy rain at S-POL
04:28-04:32 Ran vertically pointing scan.
04:38 Ran PSI tester (1200 samples, 0.01 ° /sec, from 1.5-2 ° elevation).
04:40 Resynched 10-tilt 360 ° surveys.
04:45 Convective line consists of cells at different stages of development and spacing. It is not solid, but very unsteady and multicellular. Deep towers are spread densely around S-Pol.
04:50 Spread out angles more on 10-tilts to reach 13° , not just 10.7 ° (1.5 ° spacing).
05:00 Will keep in 360 ° surv. Mode for benefit of polarimetric / electrical data comparison. If I switched to rain gauge scans, we would lose this. And we have rain gauge scans-a-plenty already.
06:21 Eastern hemisphere largely filled with stratiform echo with enhanced reflectivity 30-60 km behind the convective line. Convective line is about 60 km west of S-pol now and only pockets of very heavy rain persist. The storms are still electrified barely enough to create lightning as evidenced by 1 visual flash noted over 3 minutes of outside observing time.
07:43 Areal coverage is about 90%. Lots of stratiform with bright band signature.
08:42 Now convection is firing up again 120 km to the NW of SPOL, possibly still over gust front surging westward. Behind the line, 120 km to the SSE, deep convection has initiated where stratiform deck had cleared.
10:45 Eastern hemisphere starting to clear up. Most other precip. Appears stratiform in nature.
11:20 Switching to survey 2 again. Better vertical resolution (slightly), but only to 10.7° . el.
11:20 Noticed that precipitation estimates are biased high at 1.1° . el. Because of bright band at large ranges.
12:51 Echoes slowly moving and receding to the west, tops are to 8 – 11 km AGL. Reflectivities and Zdr low (35 dBZ max, generally < 1 dB). Almost no echo left in lobes.
14:20 Resynched 360’s to 10’s.
15:30 Citation scheduled for 17:30. Nothing out there.
16:19 First small cells popping in region two to NE 100 – 120 km; 6km tops AGL; also cells propagating into farthest range at 165 az.
16:50 Resynched to 10’s. Citation scheduled for 18:00Z or later takeoff.
17:36 Did some RHI’s between surv. Scans on small cells to NE (32 to 37° .).
17:55 Ran more RHI’s between surv scans on small cells to NE (32-40), in between surv scans.
18:05 We are back on 10’s.
18:25 Called TOGA (cell/desk out) and advised to citation flight (takeoff at 18:30 Z), both still on surv for now.
18:45 Cells continue to develop to the E of SPOL to N and S, but generally not too vertically developed and at ranges greater than 80 km.
18:57 Running RHI’s of each angel and +-1 ° (37,43,6,65,73,79) to scan possible targets for Citation. All simple warm rain cells.
19:09 Started sectors (120° ) centered at 75 ° one sector in last 10, then started pattern of far polsec loop (120 sector, RHI’s, 360 2-tilt, RHI’s)
19:20 This ten running this series
1) PPI (120 ° cent. On 75° ), 2) 2 tilt 360, 3)PPI cutoff at 10 min./should be topping
19:30 1) PPI (120 cent on 75) to
2) 2 tilt 360 (1.1 & ½ of 0.7)
still many rain cells, citation flying and seeing large rain drops
19:40 1) PPI (120 on 75)
2) 2 tilt 360 (1.1 & 0.7)
4)PPI (120 on 75) to 7.1 ° el.
19:50 1) PPI (120 on 75) to 7.1 ° el. Citation Temp at 18,000 ft. is –4.4 ° C
3) 2 tilt 360 (1.1 & 90% of 0.7)
20:00 1) PPI (120 on 75) to 7.1 ° el.
2) RHI’s (80-104)
3)2 tilt 360
Citation saw ice at –5 ° C. Saw small graupel and columns – Citation 20:05, 500 micron graupel 300 micron drizzle, -5 ° C – Citation 20:10
20:22 Shifted far polsec to 352à 112
20:33 Shifted to TrMM1.scn 45 ° -315 ° for 90 ° sector 8-12 ° az for RHI’s and a 2 tilt survey 360 °
20:36 Started ja-RHI’s till the 10’s. Pilots of Citation report very little convection
20:40 Start loop of 90 ° hires 10 ° 24’ 61 ° 38’ turret pass by citation 10 ° 18’ 61 ° 38’ 3rd turret 10,000 ft.
20:52 Moved RHI’s to 8-24 ° 30 sec too long
20:56 Dropped some of the upper elevations on the 90° sector to add some more RHI’s 10-24 °
21:00 Resynched on the 10’s
21:06 Report from Citation on 10° 18’ 61 ° 40’ northbound leg
21:10 Citation goes through the southern towers
21:17 18,000 ft. run 10 ° 30’ 61 ° 43’ cell. Cells stronger on southern edge
21:21 citation goes home
21:58 Shifting to survey as storms die out
let vertical scans go for at least 3 sweeps to get enough data
23:11 Nearly completely clear skies.
February 19, 1999
04:18 Resynched to 10’s.
05:06 NW quadrant beginning to fill in with light precip. > 80 km range.
10:08 Aforementioned precip weakened and slid to the south, probably without even registering more than a millimeter on the rain gauges.
12:00 10 minute scans were about 5 minutes off by the time I realized. I had taken the top elevation angle out of the sequence and not replaced it later. It’s all better now. The precip is still dissipating. Not much else is happening.
13:03 Did a vertically pointing scan into nothing or maybe cirrus (by accident for about 2 minutes). Started surv. 360’s late.
13:50 Resynched surv. Scans to 10’s.
14:30 Zebra, HY-ID, and Spol-gate were locked up. Brought them down and back up. Data manager and SPOL-RDA were fine so data collection was uninterrupted. Some cells in W lobe with 6km tops AGL and Zh to 30 dBZ. Still running surv. Scans. Citation scheduled for 18Z takeoff.
14:54 The ‘cells’ in the W lobe have their highest reflectivities at 4 to 4.5 km i.e. it is just the melting level, reflectivities are low at lower el. Angles, so rain probably isn’t or barely reaching the ground.
15:09 Cells forming 4-8km AGL tops at 120+ km range to ENE.
15:54 Cells kept forming and merged into a nice continuous line 100-130 km range to the E of SPOL. Ran surv., then PPI to 11 deg, then RHI’s.
16:00 In addition to line to E, cells have popped up to S of radar, in E lobe and to N of E lobe. Can’t reach TOGA – line is entering E lobe (on W side of line).
16:20 RHI’s and PPI’s on line to E. Line is slightly more intense in each cell further to the south in the line. Peak reflectivities in cells from 45-55 dBZ, Zdr’s peak from 2-3.5 dB.
16:30 We will see how the line stands up against the ridge it is headed for, for now PSI shows good shifts, precip. ID and rainfall estimates indicate some areas of heavy rain.
16:42 Line’s structure has broken down to south and some holes in dBZ now. Scans show this is mostly a warm rain event, not much Zh above 5 or 6 km. TOGA is in sectors (their latest time they could have switched from surv. To sectors is 16:40) from their 0 deg to 150 deg az. We have dd on N portion of the complex – the E lobe.
17:16 Complex is 70-100 km away in E side of E dd lobe. Not linear any more but still maintaining strength.
17:30 Convection becoming more widespread over E lobe, some cells are closing on the profiler and I will include some RHI’s over it.
17:50 Switched from 2 x 90 deg, 2 x RHI & Surv. To 1 x 135 + RHI + surv.
18:11 Widespread deep convection throughout E lobe and to south (not scanning with sectors).
18:24 Profiler is being mashed now with a good cell.
18:43 Ran specific RHI’s to test intensity at citation flight level. Citation at 7 km seeing irregular ice from previous convection.
19:01 Citation switching to W lobe cells. Good RHI’s into this complex which is outside of all the debris from other storms to the E, N, S. TOGA should switch soon. Topping at 19.3 deg.
19:11 Cells Citation is on are just near TOGA on baseline, Citation keeps swapping cells.
20:08 Starting 2 tilt surveillance, RHI’s sector 242-252 RHI’s top nearest cells
20:24 Citation goes home.
20:27 Started a meso-Dd-W on cells growing to the SW.
20:30:51 Started the 2 tilt survey.
20:33 Started a HIRES DD ja to get the cells to the SW.
20:43 TV crew is here switched to survey scan so they can get pictures.
22:00 TV crew left. Convection is dying out as the sun goes down. Only a few echoes of > 20 dBZ left.
22:34 Flat-plate sensor shut down since there aren’t any storms with 60 km.
23:37 Cells from SE beginning to become important
February 20, 1999
00:20 Cells in SE have reached the 35-40 dBZ level.
00:50 Started a set of RHI’s on the cells to the SE, they reached up to 45 dBZ, but began to die after about 00:40.
01:17 Shifted RHI’s to the SE.
01:35 ZEBRA crashed on HY-ID restarted
02:20 Shifted to surveillance scans.
07:11 Not much of anything on radar screen.
11:09 Still Nothing.
14:00 Had visitors, weather is quiet.
16:13 Cells started around 14:50, now some are slightly organized moving SW at N reaches of E dd lobe, 12 km AGL tops, some Zdr to 2.5 dB, peak Zh of 55 dBZ. Called TOGA may switch to sectors in 20 or 30 minutes.
16:31 In the 16:20:31 1.1 el. Scan you can see the boundary layer cumulus clouds and those cells which have popped up. TOGA is doing study with sounding so doesn’t want to switch to sectors yet—will at 17Z. I will start sectors at 16:40
16:44 Running 135 sector centered at 58 az to catch N half of convection to the E (missing some to the south on sector) Tops are 12-14 km AGL n these storms as seen in PPI. Running RHI’s around 26 and 105 deg az.
17:04 Storms continue to move from E to W, still organized in clusters of cells. Still doing E lobe 1x135 sector, 2 tilt surv and a few RHI’s.
17:30 TOGA called and is now scanning sectors starting at 17:20. Dual Doppler now.
17:54 Complex in E lobe has lost some intensity but complex to E outside lobe has been redeveloping on S flank, had 45 dBZ to 7km AGL, otherwise 40 dBZ seemed capped by the freezing level or 5 km.
17:59 Nice RHI’s* (24-32 by 2, 88, 90, 117-125*) Growing cells around 120-125 Az.
18:08 N side of due east complex has outflow and new development. This might propagate to the profiler eventually.
18:10 Doing 145 sector and will try to do 2 sectors to help coordinate plane (Citation was just entering area about at profiler).
18:47 RHI’s at 60 +/- 8 deg az. Cells Citation flying (105.8, 61.27). Citation sees water drops at 19,000 ft
18:57 Citation saw distinctly different at 21,000 ft ice/graupel etc. same at 22,000 ft, no water. New cells at (111.1,61.39) CPI not working
19:12 Now running 2x90 deg sectors on line of cells W to E about 20 km N and to E of SPOL. Rapid update on line important to keep up with plane.
19:30 2x90 deg. sectors, 1.1 360 surv scan, RHI’s (23, 38-51 some by 2).
19:46 Line continues to move to W and N approaching profiler from SE.
20:00 RHI’s very nice at 14 and 16 deg az. Cells almost backed into profiler. Citation starting spiral descent (in line to the E of most intense cells). Not topping strongest cell with PPI (RHI did top all but anvil overhang).
20:13 Shifted PPI sectors to 62.5 -> 337.5
20:29 Shifted PPI sectors to 53.5 -> 328.5
20:40 Raised the top PPI elevation to 23.0 over the 53.5 -> 328.5 sector to clear the storm top added 1 deg RHI step between 10 – 30 deg and added the 0.7 survey.
21:15 Line of storms north of radar have shot there wad and are dying out. Cell on the western is the only one active, but it’s on the radar baseline.
21:50 Shifted to trmm6 to get a couple of 90 sectors on the cells to the east they may develop.
February 21, 1999
00:00 Shifted to the meso far dd to get the mediocre convection to the west of the radar it has shown some signs of redeveloping I can’t reach TOGA to see what they are doing.
00:55 Cells to the west have turned into an amorphous rain shield. With max 25 dBZ echoes if they continue to decline I will shift to survey mode. There are some high dBZ cells just entering on the east edge of radar.
01:00 Resynch on the hour.
01:10 Lightning seen to the distant east.
01:40 Resynched on the 10’s. Cell to the southeast is growing.
03:20 Turned over to survey loop.
04:40 Resynched 360’s, nada on scope. PC clock was off UTC a bit, reset.
06:47 Scanning PC had crashed, not sure how long, but controller had continued 10 tilt 360’s. A weak complex to the E has moved to 115-135 km range w/ 9km tops and peak 30 + dBZ echoes. Resetting computer (MARPC2) Controller stopped scanning from ~ 6:49-6:57. Rebooted and started over survey 2 in trmm4.scn. Will resynch to 10’s at 07:00Z.
07:50 Cells weakening at 100+ km range. Scan computer died again (MARPC2).
10:49 Similar small clusters of cells occur in last few hours to E, S, N at ranges > 80 km with low peak echoes (<40dBZ). Low level winds from NNW to SSE, upper levels from WSW to ENE. Foggy locally since at least 07Z.
11:54 System to due N is persisting and even backbuilding close to N edge of E lobe. Also some echo to far SSE. Tops to 12 km AGL.
12:05 Early start for small cells already popping in E lobe.
12:24 Organization and growth continues to N and SSE. One isolated cell at 95 km range in E lobe has top to 12 km.
13:07 Scan controller restarted.
13:30 Started a TRMM3 polar sector scan near polar sector RHI’s cover the cells that’s moving into the dual-Doppler lobe. These have reflectivities up to 45 dBZ. Seems to have formed on west of topography.
13:36 Shifted center of PPI scan to 0 so range is 300-60. This allows for a longer time between changes. Cells along 20 azm. Have tops to 12km. TOGA is watching the demise of the large complex moving outside of SPOL’s range.
14:46 Cells along northern edge of eastern dd lobe have spread over a large area and begun to decline reflectivities have dropped under 30 dBZ with the exception of isolated new cells which pop up and die. These are becoming more organized.
14:55 Moved RHI’s to better cover the organizing cells. Tops are still under 10 km.
15:00 A cell near 45 77km is strengthening moving RHI’s again to cover this cell.
15:16 Moved PPI sector to 345-105 to watch the eastern cells which are developing. Western cells are dying out.
15:26 Shifted to a 90 sector (0-90) with RHI’s at 45-55.
15:30 Synced on the 10’s.
15:40 Cells along 52 have reached up to 13.4 km. Cells are moving toward radar from the NE. There is a weak cell movement is from the NE but features remain roughly stationary.
16:51 TRMM4 survey scans started. Flat plate started 16:52:45.
17:30 Shifted to a survey RHI loop with RHI’s at 352-358 by 2, 0-10 by 5, 73-88 by 3.
17:54 ER2 arrives in target area
11 30’ 61 17’
10 42’ 62 43’
17:58 RHI’s along 110-115 where ER2 is flying.
18:01:5 Survey 2 loops
18:07 ER2 starts turning on the line
18:09 Citation still on the ground due to heavy rain at Porto Velho.
18:139? Citation gets a break and the rain and leaves Porto Velho.
18:17 ER2 covers the line formed along:
IP 10 33’ 62 11’
FP 10 23’ 61 35’
18:24 RHI’s along 55-70 by 1.
18:30 2 Tilt survey
18:32 10 Tilt survey
18:56 ER2 Flying circuits over "stratiform" region along the eastern border.
19:04 RHI’s along 60-75.
19:05 Citation starting approach from 21,000’
Citation: 10 27’ 61 12’ IP
Points: 10 56’ 61 06’ FP
19:11 Survey loop restarted. Lots of stratiform precip.
19:28 RHI’s along 60-75.
19:36 Shallow echoes with strong bright band.
19:38 Citation on station at 17,000’ –3.5 C.
19:30 Survey loops started.
19:40:20 Survey was running a little long so I cut it off and restarted it.
19:48 Started RHI’s 60-70. Survey 360’s.
19:59 Started RHI’s through 3 areas.
20:00 Running at 6.5 deg/sec instead of 6.1 deg/sec.
20:08 Citation at 17,000’. They lost the CPI 10 minutes ago, but only after recording some good pictures.
20:21 Noticing that RHI’s don’t always begin at the correct azimuth. If there is a large gap between angles of azimuth, the bottom of the RHI’s gets screwed up as the beam begins it’s upward journey before it reaches the desired azimuth.
20:47 Citation is on its way home very shortly. Documented the bright band and other parts of stratiform area during the flight very well.
20:50 ER2 will finish its leg and "bug out." Scan rate switched back to 6.1 deg/sec.
21:20 Stratiform precip. That was being flown through is breaking up now only strong convection is in an E-W line 100km S of SPOL. Cloud streets are evident in the low levels ~ parallel to low-level wind. (N-S aligned).
22:09 Antenna stopped for maintenance. It’s making a funny sound.
22:34 Maintenance check revealed nothing out of the ordinary, and the metallic clicking stopped.
22:38 At 45 azm. 50 km range there is a pretty swirl in the clouds. Both Zh and Vr pick it up.
22:41 Slowly resynching the Survey 2’s.
22:51 Turned on the flat plate just in case of flashes from isolated cell 22 km to WNW. Saw flashes, but way to the south from cells 80+ km away. Rate was ~ 0.5 per minute.
22:59 Ran 3 RHI’s through nearby cells. Particle ID algorithm detected graupel/sm hail up to 6.1 km AGL in these cells. But they were still only 8 or 9 km tall.
23:15 Broad deck of stratiform rain covers SE hemisphere with areas of embedded convection. 20 to 40 km to the W are some convective cells.
23:20 Started 135 deg sector to cover these cells and some embedded convection to the S.
23:33 Didn’t top the nearby cells with 15 deg. Will add more elevation angles.
23:41-23:46 Went outside – light rain with no visible lightning.
February 22, 1999
00:00 Cells have merged into a NW-SE line with new development on the southern end. This is all about 25 km away from S-Pol. The line could be extrapolated SEward into a line o enhanced reflectivity within the stratiform precipitation. In some cells, radar tops reach 13 km and graupel/ sm. Hail reaches 8 km AGL. Wouldn’t be surprised if they start producing lightning. They are all growing beneath a thickening anvil, so it may be glaciating all the supercooled liquid water, and not allow lightning. This will be an interesting case.
01:17 convection is weaker now, with less vertical development.
01:39 Switched to 360 deg surveys.
03:24 Stratiform precip. Covers large part of southern half of radar scope. Northern half is covered, but to a lesser extent and with embedded weak convection. The intensity trend is: decaying.
04:43 There are some cells to the NE and SE that refuse to die. They start developing just outside of the radars range, move into the 140-160 km range, and then slowly decay.
04:59 Cells to the NE may hang together long enough to reach us.
05:00 Scan synchronized.
05:30 Cells to the SE continue to form and die. NE cells hang together longer and make it to the edge of the dual-Doppler lobe.
06:20 There is an interesting S-shape of the echoes in the dual-Doppler lobe. The S is made up of the 25-30 dBZ echoes.
06:50 Set up an RHI sequence for the top of the hour.
07:10 Started RHI segment.
07:10:30 Restarted the survey will restart RHI’s in 5 min.
07:25 Started the RHI sequence 37à 48 for 2 passes.
07:30 Restarted survey cells continue to weaken as they enter the dual-Doppler lobes.
07:46 Light rain/ drizzle outside.
09:30 Rain/drizzle stops.
10:20 Scans resynchronized.
10:40 Convection/Stratiform has slowly stopped drifting to the WSW. Larger cells to the E have begun to die out. Motion of the cells is more toward the S.
11:07 Large cell(s) along 60 deg hasn’t moved while the other "stuff" has moved southward. Cell is dying out.
12:00 Resynch at 12:00:01.
13:23 Some weak echo remains to NW and far SSE.
14:10 Less echo, resynched surv. Scans.
15:00 For last hour or so, boundary layer cloud field shows nicely in low level scans.
15:55 Popcorn convection beginning.
16:42 Widespread shallow convection, stopped 10-tilt after 8 and ran RHI’s. Tops to 7-9 km. Quick lifestyle looking cells. Some cores to 50 dBZ, and 3 dB Zdr, but very small strong cores. Most obvious sign of melting level is in Zdr enhancement.
17:01 Running RHI’s then small sector 0.7 and 1.1 deg el. PPI’s over profiler possibly catching light rain there. Start 360 deg surv. At 17:02.
17:19 Only place not raining near the rain gauges. All convection moving to S. Resynched scans.
18:16 Similar story still, ran some RHI’s. Tops to 9 km max, most less. Once again, can be high reflectivity cores (even > 55 dBZ) and high Zdr ( > 3 dB), but cores generally are very short lived.
20:13 Brief moderate rain shower here, complete with sun.
22:11 Except for 3 or 4 moderately intense isolated cells, all the radar scope has cleared up. Most of the smaller popcorn convection is dissipating as the sun sets.
February 23, 1999
01:04 only one cluster of cells persists. It is ~60 km away to the ESE. It has gone through several demises and regeneration’s in the past couple of hours.
01:30 There are some cells very close to S-Pol that aren’t being topped. (5-10 km to the SE).
01:37 Running RHI’s towards the SE to probe these close cells. There is a Zdr column that is very narrow up to 5.7 km AGL. These cells are still only 8 or 9 km high. But they are the only batch of convection on the scope so I’m running trmm1.scn meso dd e ( a 135 deg sector up to 31.6 deg elev.) centered on 135 deg az.
01:54 They are too close for PPI’s. I’m going to RHI’s. Some tops are to 10.8 km AGL.
02:05-02:30 Creating a sequence of RHI’s to capture convective scale motions. Time resolution is ~32 seconds. Repeated RHI’s taken at 155 deg azimuth approximately parallel to the direction of propagation. This makes for a very mice animation when looped. Only one break in animation during 360 deg surveillance time.
02:30 Back to 10-tilt 360 deg surv. Enough fun.
06:41:57 Started a single azm along 169 deg.
06:50 Restarted survey loop
09:11 Heavy fog is just beginning to clear due to light drizzle.
10:30 Made two GIF loops of velocity and reflectivity RHI’s
11:22 Started a few RHI’s along 5-9 deg.
11:27 Restarted survey.
12:27 Still on survey. Moderate echoes typically less than 30 dBZ max along radial west of radar, some to S and N within 80 km also. Velocity field plus velocity in RHI movie loop made a little earlier shows stronger winds and more shear than I’ve seen here before, but echoes are weakening.
15:10 Convective cells began mostly on E side of SPOL range near ridge tops and started propagating from their positions to the SE. Cells to the E at a range of 60-80 km are the most intense with peak reflectivities of > 50 dBZ and Zdr as high as 3.5 –4 dB. The cells aren’t that high with tops only 8-10 km now.
16:04 Ran Rhi’s through strongest area of convection around 121 deg az. Good high tops > 15 km now. Good strong cores high Zdr, phase shift, but all strong cores tied mostly below 5 km. Citation scheduled for 19 Z takeoff, ER-2 for 17 Z so both should be in area for 21 Z overpass.
16:10 Bored, so going to run 2-tilt surveillance then short time scale 90 sector on complex, then Rhi’s for minutes to watch convective short time lifecycle.
16:30 Back to 360 10 tilt surv.
17:47 Zebra crashed a while back, now up. Last ten did some RHI’s at the strongest line of cells (centered on 85 deg) I made some nice gif images, animated they show the strong shear between the NW@ flow at low levels and SE flow aloft.
17:50 Running 360 10 tilt surv. Most of the convection is to the E and SE.
18:27 Lines still forming along NW to SE, in strong shear, not as intense lines as at 16:00 Z.
18:48 ER-2 is approaching area, will fly a line from the SE to the NW. RhI’s ran at TOGA through some weak convection.
18:56 Running 120 deg sector on old, largest line (30 deg – 150 deg)
19:00 2nd sector centered on 85 (was 90 last time).Ran RHI’s centered on 76 deg azm into anvil/old system ER2 is flying.
19:15 just ran sector-
19:37 Still running this pattern above with RHI’s spread between 25 and 105 by 10.
19:48 The dd system along azm. ~30-90 deg is dying and a line to the N to NNE is strengthening. Sector is still on old line.
19:59 Sending planes over line of storms through eastern dd lobe and northward.
20:06 TOGA is doing sectors 30 deg – 180 deg azimuth relative to TOGA. I suggested shifting counter-clockwise by 15 deg. they are doing hi-res sectors. We are not.
20:10 Will try to synch up on the 10’s
Running 125 deg sector up to 17.4 deg elev. Centered on 10 deg az.
20:18 Getting RHI’s over the profiler. The convective line is close to it.
20:25 Need to do PPI higher to top storms near the profiler.
20:40 TOGA is having trouble topping the storms on the northern part of the line. They are switching to 10 minute updates in 135 deg sectors to get everything topped. I didn’t realize TOGA was doing 5 minute updates. We’re sending the aircraft to the northern part of the convective line.
20:50 I thought something was wrong, but it wasn’t. The real-time display is not capable of switching fields, but otherwise everything is functioning okay for the TRMM satellite overpass.
21:00 Got some RHI’s over the profiler again as satellite passes over.
Stellar, capped columns, one lightning flash and bounciness in Citation as satellite passed over.
21:25 ER-2 pilot saw what he called a sprite to the N. He says it was whitish-blue and came upwards from the cloud top at an angle. Sounds like a classic blue jet description. (note this was in daylight)
21:50 ER-2 cont. to fly area centered on spot 100 km to the N.
22:00 ER-2 on its way home.
22:20 Switched to 360 deg surv. Scans. (10 tilts) convection is dissipating across the whole radar scope.
February 24, 1999
00:30 There is nothing of great consequence except for a packet of storms in the far western DD lobe. It is being topped just fine by the 10-tilt 360 deg surveys. And they are all started on the 10’s.
03:08 The packet of storms slowly drifted off to the SE, out of the lobe. Its anvil is being blown off to the NW, however. Some very shallow precipitation has developed ~20km N of S-Pol. And there is some unorganized convection 150 km to the SE.
04:35 Started and RHI sector along 180deg –190deg
04:40 restart 2 tile survey
04:43 RHI’s along 160 deg-170deg
04:50 Restart 2 tilt survey
06:01:31 Restarted survey 2 late after 10 min of RHI along 158-160
07:46 A "packet" of storms is drifting in from the NW will take a group of RHI’s at 07:50.
08:00 restarted survey 2
09:35 The "packet" of storms have reached the radar and it has begun to rain. Large cell to the NW small bands moving across NW-SE orientation, but movement parallel to band.
10:37 RHI’s along storm cell to the NW 2 parallel band to the N of radar oriented NWà SE
10:43 strong NW flow
11:10 RHI’s along band to the N
12:00 System down for ? , tech reason. 12:00-12:30
12:13 Surv. Scans restarted. Large stratiform "line" of echo is sliding , or echoes are moving along the orientation of the line. Line stretches from due N at far ranges in to just short of profiler and out to e.
12:48 Ran profiler and raingauge #1 scans since there may be some light rain over the site. Started surv 10 tilt late at 12:52. Echoes up to 30 dBZ only on northern most rain gauges.
13:30 Made a modified 10 minute surv. Scan with 8 tilts, which almost tops storm (not doing dd now), and runs 3 minutes of profiler / #1 rain gauge scans.
13:57 Screwed up profiler/rain gauge PPI commands so scans were not made correctly. Should work this round. Still weak echo over site. Lines most intense echoes have moved to the NE.
14:18 Not much echo (10 dBZ max) over profiler, switching back to 10 tilt 360 deg. PC clock reset closer to UTC (MARPC2).
15:10 Running new 360 surv. With following el. Angle scans: (0.7, 1.1, 2.3, 3.5, 1.1, 4.7, 5.9, 1.1, 7.1, 8.3) has a low elevation scan at least every third scan, to get more hi-resolution rainfall information. I’ll call this HIRAIN, surv scans.
15:18 Running #1/Profiler scans, since edge of stratiform is over again.
15:43 Still 20+ dBZ over some of #1 gauges, stay with for more time.
16:05 Stopped rain gauge scans, low Zh (<10 dBZ) over site. Back to HIRAIN surv. Scans.
16:20 Resynch. To 10’s, same scans. System is just decaying, at low levels has no echoes > 25 dBZ closer than 80 km and 35 dBZ is 120 km distant. At upper levels anvil hangs further over profiler and raingauges, but rain is probably no longer reaching the ground here much.
17:57 Lines of cells forming to S of SPOL, some to E and some in W lobe. Cells form in a line and propagate along line. 10-12 km tops outside lobe at most intense section, 6-8 km tops in forming cells in lobe.
18:16 Cutting off last two upper el. Sweeps to do some RHI’s to S-SSE at cells in these lines, these slices are mostly through the line unlike RHI’s from the last two days which were along line, generally.
18:58 Cells continue in lines which run almost W to E. They propagate and change so quickly I’ve thrown around the dd idea, but think it wouldn’t be reasonable catch the time scale of the cells and their movement. For now continuing with 10 tilt survey with extra 1.1 scans with at least 4 min resolution, 3 min if you consider 0.7 as an additional set of low level rainfall information.
20:43 Doing RHI’s through line to the SE.
20:50 Back to regular 10-tilt 360 deg surv.
21:30 Various storms are close by. Within 25 km of S-Pol there are storms to the NW, N, and SE. It would be impossible to top all the storms in 10 minutes, so flat plate data, if it were being collected, would be dubious, at best, for this time. We wouldn’t know which group of storms the flashes would be coming from.
21:49 2 km AGL, there is a 14 m/s west wind. This is the most I have seen since I have been here (4 weeks)
February 25, 1999
01:05 2 km winds now swinging to the SW. Scattered patches of stratiform precip with widely scattered cells rule the radar scope. None are very deep.
05:46 Weak echo in entire S half of area, now spreading all over. Going to add 1.1 scans so 1.1 resolution is 3 minutes.
07:50 Echoes decreased but still widespread. Looks like sfc winds from the E and mid winds from NW.
16:40 Shifted to a hires dd-ja with origin at 10 width 90 with a hires ja RHI 4-14 deg. for a patch of cells to the North of SPOL called TOGA and arranged for them to do a dual Doppler sector
17:32 Shifted dd sector center is at 25 deg. tops near 14 km for the cells being scanned.
17:57 TOGA called to say they need to shift out for the rain gauge people.
18:17 TOGA Back on DD
18:20 Shifted to a 135 sector. RHI’s at 45-48
18:24 Shifted RHI’s to 52-55.
18:30 Running sequence by hand.
18:58 Pick the scan for RHI’s badly out sync now
19:06 PMAC error started RHI’s only.
19:40 Running 135 sector over western DD lobe. Updates every 10 minutes. Elevation angles up to 28 deg. top storms with one angle to spare.
20:04 TOGA switched from sectors over the western DD lobe to 360 deg. surv. The activity is diminishing in that area.
21:20 Have been rotating 135 sector clockwise to capture active convection sliding into eastern DD lobe.
21:41 Running rain gauge scans. #2 has heavy rain.
21:52 Running 90 sectors to the North with 5 minute spacing (hires).
21:58 360 surv. At 1.1 completed.
21:59 Doing RHI’s now.
22:00 Another 90 sector to the North.
22:09 Continuing w/ 5 minute spacing for sectors.
22:29 RHI’s over profiler. It’s getting heavy rain nearby.
22:37 TOGA’s telephone is busy. That’s okay, the heavy rainers in the eastern DD lobe aren’t very vertically developed, so coordinated hi-res scans aren’t necessary.
22:49 RHI’s over gauge network #2.
23:07 Continuing sectors to the North. Two every 10 minutes. Angles include 0.7 and 1.2 to match the angles I believe trmm2.scn uses. Width of sector and max elevation have evolved along with the storm system. (ie higher storm means narrower sector is required).
23:39 More RHI’s over profiler and gauge site #1.
23:49 Tops in the strongest cells reach 14 km. There is some good reflectivity above the freezing level in some places too. Hy-ID algorithm indicates virtually no graupel, however. Just a boring transition from liquid to solid as you go through the freezing level.
February 26, 1999
00:13 Every 3 or 4 min you have a new sweep at either 1.1 or 1.2 over the rain gauges. For the last hour, RHI’s over the airport have been also included. Mostly stratiform rain covers a large fraction of the eastern DD lobe. They’re 16 km high to the east (100 km out).
01:00 Some heavier rain might move over gauge #3.
01:20 Starting #2,#3,#4 loop (trmm2.scn) All 3 sites could get wet.
01:21 Noticing quite a bit of phase shift through the ice portion of the clouds in the rear of the main convective line 100km to the east. Will be interesting to see the Kdp’s when they are eventually computed.
01:40 Rain is moving away from gauges, so switched to 10 –tilt 360’s.
03:08- Running vertically pointing scan. 40 dBZ rain is overhead. Sometimes 45 dBZ.
03:22 Back in surv mode. Still heavy rain at SPOL.
03:38 Going to run a vertically pointing scan during this ten, ie 8 minutes of v. pointing and a 2 Tilt 360.
03:49 Going back to surv, but instead of regular 10-Tilt doing a frequent 1.1 el. Scans – (ie 0.7, 1.1, 2.3, 3.5, 1.1, 4.7, 5.9, 1.1, 7.1, 8.3) ie a low level (1.1 or 0.7) at least every 3 minutes. May run another vertically pointing next ten since rainband looks centered over us now.
04:00 V Pointing, still heavily raining. Real time display messed, but data is still collecting.
04:10 Running trmm5.scn airport gauges sequence as moderate Zh 30+ dBZ over them now.
04:20 V Pointing, still moderate to heavy rain here.
04:30 Still moderate echo over profiler, running trmm5.scn. Some echo about 40 dBZ very near profiler.
04:40 Another profiler rain scan by default, ok, still 30-35 dBZ there.
04:50 V. Pointing scan
05:00 Doing 2x90 sectors on E lobe w/ TOGA. Topping everything but very close within 20 km.
07:58 Widespread echo has continued but intensity has slowly diminished in E lobe. Propagation is still from SW to NE. Max echoes in lobes still E lobe at 35 dBZ or so.
09:20 Shifting to 360 surv scans with high time resolution for 1.1 el angle scans. Moderate echoes in E lobe. Strong echoes to N at far range moving from W to E. Less echo to S of radar.
11:25 Shooting some RHI’s into weak complex very close to SSE (25-30km). Since 360 surv is not topping. RHI reveals low tops (6km) and low Zh (< 38 dBZ).
11:30 Resynched 10 tilt 360 surv scans w/ extra 1.1 el scans
12:30 Dual Doppler 335-85 deg.
17:14 Rain gauge scans over the profiler.
17:20 Two tilt 360 started will go back to rain gauge when it finishes.
17:30:11 Started hires dd ja sector is 8 to 90 deg RHI’s along 55 to 65 deg azm.
18:51 Earl Williams would like 360 scans with RHI’s so we shifted to manual for a few scans.
19:00 Synched on the hour.
20:10 Rain approaching rain gauge/profiler so switched to a trmm5 scan.
20:46 No more raingauge scanning, strong line of convection is directly over SPOL.
20:49 Doing slow scan through lots of phase shift. 512 samples/gate. 0.01 deg. per second.
21:04 There’s a broad convective line almost directly over SPOL stretching > 150 km from 300 deg az to 120 deg az. Solid tops up to 16km AGL. Did one RHI up to 89 deg elevation.
21:43 Convective line has weakened and broadened. Its leading edge to the north is about 15km away from TOGA and #1,#2 gauge networks. Keeping with 360 10 Tilt surv scans. Any way we cut it we will miss a good chunk of the storm complex (either above us, while in 360’s or behind us if in sector scans).
21:50 Radial velocities are mostly away from the radar at low levels, indicating divergence. Not surprisingly since we’ve been getting heavy rain near us for over an hour now.
22:43 Line is ~ 5km away from TOGA, 10km away from site #2 and profiler.
23:24 Site #2 is intercepted. Running rain gauge loop.
February 27, 1999
00:10 Back to 360 surveys.
04:50 Broad echo to south is weakening as cells in N portion of E DD lobe grow, over last couple of hours.
07:20 Far raingauge scan (trmm2.scn), as backside of echo is over sites #3 and #4. Echoes at 1.2 deg el no more than 30 dBZ at #3, and 25 dBZ at 0.7 deg el.
07:30 Back to 360 surveys.
10:20 Cells continued to grow on SE flank of system until it had backed into W lobe and now it is raining moderately at SPOL. Doing a V pointing scan into this moderate light rain. Actually looking outside the rain stopped during the scan. Ran a 1.1 deg 360 after 8 minutes of V pointing.
10:30 Running Profiler/#1 scans, trmm5. Echoes around 25-35 dBZ near profiler and increasing with propagation of echoes over site. A reflectivity gradient exists over different gauges. RHI’s show small amount of phase shift and a very distinct bright band in almost all variables. Printed RHI’s in most variables plus a particle ID image.
10:40 Continuing to run trmm5.
10:52 Still running trmm5, raining again here.
10:59 Heart of reflectivities (around 40 dBZ) right over profiler.
11:45 Rain, and echoes starting to decrease at profiler, but still present as band starts to slide to SE and weaken.
13:20 Rain moved off raingauge network shifting to trmm4 survey scan
14:59 new packet of showers entering from the NW over rain gauges shifting to a raingauge scan.
16:30 large organized cell just to the E of TOGA. Cell dBZ’s as high as 65 dBZ. TOGA will start the dual-Doppler sectors at 16:40.
16:40 Restarted with a meso dd e modified for a 1.1 deg survey tilt and RHI sequence from 333-330 deg.
17:13 Started a 10 deg wide (0-10 deg) RHI sector on line of storms in the DD sector. Thin of storms developing into a squall.
17:20 Restarted the meso dd e loop
21:23 Running 360 deg surv. With 2 elevation angle sweeps of 1.1 deg per 10 minutes. Also some Rhi’s included.
22:20 Back to normal 10-tilt 360 deg surveillance.
February 28, 1999
00:00 All quadrants are exhibiting little precipitation. What was once moderate stratiform precip has now fallen out. There is an area of isolated convection passing over site #3 now, but its also breaking up.
01:40 Zebra locked up. So Tim rebooted it at 01:45
03:17 In the next shift, there will probably be a chance to run slow 360’s. Most precip is light and diminishing.
03:40 Just one "blob" of echo max 30 dBZ at 1.1 el.
04:33 Just a little echo left going to run slow scan, 360 surv at 1.5 deg per second at 0.5, 0.7, 0.9 and 1.1 deg elevation, started at 04:34.
05:01 Back to regular surv scans.
08:32 Small shallow cells have formed, mostly to the south, all are < 40 dBZ, most are < 30 dBZ, very little rain in these yet.
10:15 Strangely, at least against what I’d expected, the weak echoes died off before they amounted to anything, except for some which has persisted to the SE and SW.
11:33 Mostly quiet, with a bird burst as usual.
12:30 Did a slow scan 0.1 deg steps from 0.4 deg to 1.4 deg to get ground clutter. Disk filed on Spol-RDA because of slow scan restarted tape writer after solar.
13:22?? Slow scan stopped solar scan started some clouds remain over the sun.
14:05 Calibrations finished processor restarted will start scans at 14:10
14:10 Scans filled disk had troubles clearing the queue on POL-RDA
14:50 Problems cured by clearing…/save rather than …/forTape
17:26 Most of the cells are in NE lobe
19:30 Scattered shower ~35 to dBZ ; survey2
20:33 Heavy rain dropping in a line just S of S-Pol.
20:40-20:48 Ran 0-89 deg elevation RHI’s through line.
20:50 tops are hard to 17.5 km AGL.
20:55 More RHI’s as line passes over. It’s spreading out slowly.
21:20-21:26 Will try a vertically pointing scan. Did it.
21:28 one more survey set. Line is weakening and spreading out.
22:00 Stopping the radar.