CASE 9 - Organized cellular activity to N & SE

7/19/04

Microphysical scans 0815 - 1200 Z, 3h 45m

 

 

SYNOPTIC CONDITIONS SUMMARY:

 

 

Synoptic feature map -

IOP status - No IOP called at this time.

 

NW-SE oriented ridge axis elongated further during period.

 

Dry-line boundary present parallel to west coast of Mexico - responsible for convective initiation producing some MCSs

 

An MCS formed in the region of weak inertial stability / 250 mb jet later in this period (near 12Z).

 

 

Day 0 forecast discussion text

 

Winds

200 mb - model.ETA.200407191200.00_200mb_wnd.gif

500 mb - model.ETA.200407191200.00_500mb_wnd.gif

700 mb - model.ETA.200407191200.00_700mb_wnd.gif

850 mb - model.ETA.200407191200.00_850mb_wnd.gif

 

Mazatlan SkewT - ops.SkewT.200407191200.Mazatlan_MX.gif

 

 

 

EVENT SUMMARY:

 

24 h precipitation totals -

 

 

S-POL SUMMARY: Scattered deep cells over the SMO to the N and E/SE of S-Pol. Storms exhibited more organization today than usual. They have a preferred E-W orientation and ~40 km spacing.

 

S-Pol log - spol_071904.txt

 

SCAN OVERVIEW:

 

0815 Z

Begin Microphysical Scanning, Switched to MicroNear90: Cells to the N producing lots of lightning.

 

0815Z, Base reflectivity

 

0825 Z

3 scans / 15 min over NOAA profiler: Moderate rain over NOAA profiler. Translating sector CCW to stay with storms to the N.

 

0830Z, Base reflectivity

 

0830, Reflectivity Cross Section - Intense cell N of S-Pol. Generally, cells were intense (55+ dBZ) and deep (17 km)

 

0830, ZDR Cross Section - Intense cell N of S-Pol

 

 

 

0852 Z

Storms developing close to S-Pol (<10 km N). Storms appear shallow.

 

0923 Z

Translating sector CW to center on with <10km storms. By 0933 Z, target storms are dying.

 

0930Z, Base reflectivity

 

0944 Z

Re-centering sector to capture intense storms to the E.

 

1000 Z

Storms to the E looking organized, assuming an E-W orientation w/ ~40 km spacing.

 

1000Z, Base reflectivity

 

1019 Z

Large storm developing to SE - not contained in current sector scans. Large storm enters sector scans ~1040 Z.

 

1015Z, Base reflectivity

 

1100 Z

Switching to MicroFar135: Lighting visible from S-Pol at 1121 Z.

 

1100Z, Base reflectivity

 

1200 Z

End Microphysical Scanning, Switched to ClimoFar: Radar left unattended.