Flood Risk AL/FL/GA
From
Mike Powell@618:250/10 to
All on Fri Oct 9 14:07:42 2026
AWUS01 KWNH 091703
FFGMPD
FLZ000-GAZ000-ALZ000-092300-
Mesoscale Precipitation Discussion 1462
NWS Weather Prediction Center College Park MD
101 PM EDT Fri Oct 09 2026
Areas affected...Southern AL...FL Panhandle...Southwest GA
Concerning...Heavy rainfall...Flash flooding possible
Valid 091700Z - 092300Z
SUMMARY...Heavy rainfall associated with Hurricane Isaias will
continue to lift north over the next several hours across southern
AL, the FL Panhandle, and southwest GA. The threat for flash
flooding will gradually increase with time.
DISCUSSION...The latest GOES-E IR satellite imagery along with
conventional radar mosaics show the eye of Hurricane Isaias
continuing its approach to the FL Panhandle. As the storm
continues to lift north this afternoon, it will be increasingly
interacting with a frontal zone draped around the north side of
the storm's circulation.
Deep and strongly convergent southerly low to mid-level flow
around the eastern flank of the storm will surge north across the
FL Panhandle over the next several hours. This will foster an
expanding shield of heavy rainfall more regionally via deep
warm/moist air advection and associated isentropic ascent.
Gradually the poleward transport of instability will favor the
development and expansion of convection near and north of the
front in an elevated fashion. However, core instability-driven
convective bands associated with Isaias will be focusing farther
south, but will be lifting north around the storm's eastern
semicircle toward the FL Panhandle.
A nose of MUCAPE values across the eastern Gulf of America are on
the order of 1500 to 2500 J/kg in association with the deep layer
southerly flow, and much of the stronger convective banding will
be aligned with this instability axis in conjunction with stronger
low-level convergence. Central convection associated with the core
of Isaias will likely still remain largely offshore until later
this afternoon, but rainfall rates are expected to increase ahead
of this as strong deep layer forcing increases along with outer
convective banding features.
Rainfall rates of up to 1 inch/hour can be expected to arrive by
around 21Z (4PM CDT), with rates potentially reaching 2+
inches/hour shortly thereafter. These rainfall rates and an
expected increase in cell-training concerns should support some 3
to 5+ inch totals by early this evening, and this is consistent
with the 12Z HREF/REFS guidance.
FFG are very high across the region, so initially the soils/ground
conditions should be able to accommodate the front-end rainfall
ahead Isaias' central convection and impending landfall in the
western FL Panhandle, but as the rates increase and begin
involving more urbanized areas, the concerns for flash flooding
will begin to steadily increase.
Orrison
ATTN...WFO...BMX...JAX...MOB...TAE...
ATTN...RFC...ALR...ORN...NWC...
LAT...LON 31848541 31658440 31208357 30648326 30168338
29828371 29578433 29508524 29698574 30038631
30108706 30188800 30558836 31068821 31528756
31788659
$$
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* Origin: capitolcityonline.net * KY, USA (618:250/10)