Flood Risk AL/FL
From
Mike Powell@618:250/10 to
All on Fri Sep 11 09:34:08 2026
AWUS01 KWNH 111333
FFGMPD
FLZ000-ALZ000-MSZ000-111930-
Mesoscale Precipitation Discussion 1248
NWS Weather Prediction Center College Park MD
930 AM EDT Fri Sep 11 2026
Areas affected...Southern AL...FL Panhandle
Concerning...Heavy rainfall...Flash flooding possible
Valid 111330Z - 111930Z
SUMMARY...Slow-moving bands of showers and thunderstorms with very
high rainfall rates will be capable of maintaining a threat for
flash flooding over the next several hours.
DISCUSSION...The latest GOES-E IR satellite imagery shows some
impressively cold convective tops to near -75 C across portions of
southern AL and the FL Panhandle as an axis of very moist/unstable
and convergent Gulf inflow continues around the eastern flank of a
weak low center across southern MS.
Multiple surface troughs/convergence zones are noted in the
surface observations, and this coupled with the level of moisture
and instability should maintain the convective threat over the
next several hours with a general tendency for the activity to
advance farther north and inland across southern AL.
MLCAPE values of 1500 to 2500+ J/kg are in place along with PWs of
2.25+ inches, and this combination will easily support rainfall
rates of 2 to 3 inches/hour given the level of stronger cloud-top-cooling/strong updrafts seen. This along with some
banded nature of the convection and localized cell-training
concerns will favor some spotty 3 to 5+ inch rainfall totals going
through early this afternoon.
The FFG values are rather high, but the slow-moving and locally
training character of the convection may drive sufficient totals
for some areas of flash flooding. However, overall, the antecedent
conditions on the ground would suggest this primarily being an
urban flash flood concern.
Orrison
ATTN...WFO...BMX...LIX...MOB...TAE...
ATTN...RFC...ALR...ORN...NWC...
LAT...LON 32498727 32318596 31548510 30548510 30048554
30218667 30098765 30098812 30478845 31198821
31928804
$$
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* Origin: capitolcityonline.net * KY, USA (618:250/10)