CASE 18 - Long-lived, right-turning MCS develops E of S-Pol


Microphysical scans 1930 - 2130 Z, 2h

(MCS lifetime: 1930 - 8/6 1100 Z)





Synoptic feature map - MISSING


Day 0 forecast discussion text



200 mb - model.ETA.200408060000.00_200mb_wnd.gif

500 mb - model.ETA.200408060000.00_500mb_wnd.gif

700 mb - model.ETA.200408060000.00_700mb_wnd.gif

850 mb - model.ETA.200408060000.00_850mb_wnd.gif


Mazatlan SkewT - ops.SkewT.200408062100.Mazatlan_MX.gif


EVENT SUMMARY: A quasi-linear / asymmetric MCS developed over the SMO just N of Mazatlan, propagated towards S-Pol, and then moved NW along the coastal plain.


24 h precipitation totals -





1930 Z

Deep convection initiates to the E of S-Pol, along the SMO.


1940Z, GOES-10 Vis


2030 Z

Deep convective region to the E of S-Pol growing, look more organized.


2024Z, GOES-10 Vis


2230 Z

Leading convective region takes on a linear shape w/ a trailing stratiform region to the E.


2224Z, GOES-10 Thermal IR


2300 - 8/6 1130 Z

MCS turns to the right, moving N/NW. The MCS maintains a leading convective line/complex with a trailing stratiform region (to the S/SE). Main convective activity has dissipated by 1130 Z.


0324Z, GOES-10 Thermal IR


0724Z, GOES-10 Thermal IR


1124Z, GOES-10 Thermal IR






S-Pol log - spol_080504.txt




1900 Z

Switching to ClimoFar: Cells coming into radar range at 150-180 km to the east. Cells were not being topped with ClimoShallow.


1900Z, Base reflectivity


1930 Z

Begin Microphysical Scanning, Switching to MicroFar90: Sector centered at 80 deg to capture convection coming into range from the east.


1930Z, Base reflectivity


2035 Z

Switching to MicroNear90: Convection is now being topped.


2045 Z

Switching to MicroNear135: Convection breaking out over the foothills. Log notes an interesting altocumulus deck over S-Pol. Running RHIs at 102 and 103 deg. Convection along leading line of MCS appears to be elevated (67 dBZ core at 7 km).


2100Z, Base reflectivity


2130 Z

End Microphysical Scanning, Switching to ClimoNear: Echo coverage is too great to focus on sectors.


2205 Z

Light rain at S-Pol, dissipating by 2250 Z. MCS turning right, moving N along coastal plain.


2200Z, Base reflectivity


2300 Z

Running Profiler Scans: Leading convective line passing NOAA profiler site. 40 dBZ @ profiler.


2315 Z

Classic MCS (asymmetric) moving N along coastal plain - trailing 40 dBZ stratiform stretched south of radar. Nice rear inflow jet on velocity signature. 20 m/s jet between 2-3 km from ENE behind systems. Surface divergence present at radar.


2315Z, Radial velocity