From Mike Powell@618:250/1 to All on Tue Oct 14 08:12:26 2025
AWUS01 KWNH 141239
FFGMPD
CAZ000-141838-
Mesoscale Precipitation Discussion 1196
NWS Weather Prediction Center College Park MD
839 AM EDT Tue Oct 14 2025
Areas affected...Southern CA
Concerning...Heavy rainfall...Flash flooding possible
Valid 141238Z - 141838Z
Summmary...A band of showers and thunderstorms should continue to
move east with time. Hourly rain amounts up to 1" and local
totals in the 2-4" range are possible, which would be most
problematic in area burn scars.
Discussion...A narrow plume of moisture and instability near an
incoming front and ahead of a cold low to the west-northwest of
San Luis Obispo is expected to continue moving eastward through
southern CA this morning. Precipitable water values of 1-1.1" per
GPS data and MU CAPE of 250+ J/kg exist in this region.
HREF guidance shows a high chance of 0.5"+ in an hour, though very
low chances of 1"+, which fits the available ingredients. As
instability winnows with time, the potential for 1" amounts should
decrease. The mesoscale guidance suggests local amounts in the
2-4" during the next six hours. Locations with the most concern
would be area burn scars, which would be more susceptible to
runoff/debris flows.