CASE 10 - Quasi-linear MCS over SMO, developed MCV


Microphysical scans 0100 - 0415 Z, 3h 15m

(System lifetime: 2200 - 0330 Z)







Synoptic feature map -

IOP status - IOP #3 in effect (see report). This IOP (0Z 7/20-0Z 7/23) captured the breakdown of a monsoon ridge over the domain, along with several wind surges over the GOC including a major Gulf Surge (GS#2). The outflow from this MCS/MCV event was believed to initiate a weak gulf surge in the northern GOC.


Most prominent convective activity during this time over the SMO, preceding IV#6.


Strong 250mb jet extending from La Paz, Mexico to Texas.




Day 0 forecast discussion text



200 mb - model.ETA.200407210000.00_200mb_wnd.gif

500 mb - model.ETA.200407210000.00_500mb_wnd.gif

700 mb - model.ETA.200407210000.00_700mb_wnd.gif

850 mb - model.ETA.200407210000.00_850mb_wnd.gif


Mazatlan SkewT - ops.SkewT.200407210000.Mazatlan_MX.gif



EVENT SUMMARY: A quasi-linear MCS developed over the SMO between 20-22 Z on 7/20. This MCS moved off the SMO toward the GOC during the observation period, and dissipated shortly thereafter. NOTE: The GOES-10 satellite imagery is missing from 7/20 18Z - 7/21 10Z, making it difficult to describe overall development of system.


0100Z, Base reflectivity


24 h precipitation totals -


S-POL SUMMARY: Scattered intense cells, associated with developing MCS, move through S-Pol domain. Storm motion during this time period was easterly (as are 500mb winds).


S-Pol log - spol_072104.txt




2000 (7/20) - 0100 Z

Scattered intense cells, presumable associated with developing MCS, developed E of S-Pol over the SMO.


2300 Z, Base reflectivity.


2315 Z

A cell 80 km to the N-NE of S-Pol had 50-55 dBZ and R-Kdp rainrates of 100 mm/hr.


0100 Z

Switched to MicroNear135: Sector centered on 120 deg. Prompted by a particularly intense (63 dBZ) echo that formed just E of S-Pol, moving westward. This cell exhibited good low-level convergence, good upper-level divergence, and frequent lightning (rumbling of thunder noted in S-Pol log).


0107Z, dBZ Sector of intense convective activity within MCS over SMO


0107Z, dBZ Cross Section through intense cells to east - Corresponds to yellow line drawn on PPI sector above. dBZ in core > 60.


0345 Z

Echo intensities have weakened substantially and stratiform precip dominate S-Pol domain.


0345 Z, Base reflectivity.


0400 Z

End Microphysical Scanning, Switch to ClimoNear: