CASE 8 - Cellular activity over SMO

7/17-18/04

Microphysical scans 2300 - 0230 Z, 3h 30m

 

 

 

SYNOPTIC CONDITIONS SUMMARY:

 

IOP status - No IOP at this time.

 

A ridge axis oriented NW-SE over central Mexico was pulling drier air into Tier 1 - time period characterized by low to moderate convective activity over Tier 1.

 

Prevalence of moisture at low-levels in Sinaloa region credited for thunderstorm development in S-Pol domain.

 
Synoptic feature map

 

Day 0 forecast discussion text

 

Winds

200 mb - model.ETA.200407180000.00_200mb_wnd.gif

500 mb - model.ETA.200407180000.00_500mb_wnd.gif

700 mb - model.ETA.200407180000.00_700mb_wnd.gif

850 mb - model.ETA.200407180000.00_850mb_wnd.gif

 

Mazatlan SkewT - ops.SkewT.200407180000.Mazatlan_MX.gif

 

 

EVENT SUMMARY: Groups of cells formed in the foothills and mountains during the evening hours, probably due to diurnal heating. Cell movement was generally in the W-NW direction.

 

2324 Z, GOES-10 Vis

 

24 h precipitation totals -

 

 

S-POL SUMMARY: Sector scans were initiated as cellular activity moved with 80 km of S-Pol. Several cells had tops > 16 km and ZDR columns extending ~1 km above the freezing level. Peak ZDR values below the freezing level were ~3.5 dB. New cell growth was focused upwind (east) of cells over the SMO.

 

S-Pol log - spol_071704.txt - spol_071804.txt

 

2330Z, Base Reflectivity

 

2338Z, Cross section of reflectivity in intense cell - >50 DBZ up to 10 km in the core.

 

2338 Z, Cross Section of ZDR in intense cell -

 

SCAN OVERVIEW:

 

2300

Starting MicroFar135: 135 degree sector scans centered on 70 deg.M ost active area appears to be cell group @ 60 deg az 120 km distance.

 

2345

Switching to MicroNear135: Cells close (within 50 km) of S-Pol warrants change to near-mode. Center of sector scans also changed in order to capture cells in NE quadrant.

 

0020

Cell complex to NE showing small hail on particle ID. Shifting center of sector scans to 35 deg.

 

Several cells possessing excessive anvils.

 

0150

30 km NE of S-Pol: Cells appears to have put out outflow bddy and new cell development occurring.

 

0230

End Microphysical Scanning, Switching to ClimoNear: Cell activity diminishing.