155
AWUS01 KWNH 120258
FFGMPD
FLZ000-ALZ000-MSZ000-120856-

Mesoscale Precipitation Discussion 1255
NWS Weather Prediction Center College Park MD
1057 PM EDT Fri Sep 11 2026

Areas affected...portions of the Central Gulf Coast

Concerning...Heavy rainfall...Flash flooding possible

Valid 120256Z - 120856Z

Summary...Showers and thunderstorms with heavy rainfall appear to
be somewhat increasing in coverage along small portions of the
AL/MS coast.  Hourly rain amounts to 3" with local totals to 5"
are possible, which could lead to isolated to widely scattered
flash flooding.

Discussion...An upper level low across AR is allowing for
difluence aloft across the Central Gulf Coast.  Near and behind an
outflow boundary which has tried to push offshore, new convective
development has occurred near the AL/MS coastal border and the MS
barrier islands.  A few other showers and thunderstorms have
recently formed across far southern AL and the western FL
Panhandle as well.  This is occurring within a zone of 850 hPa
confluence.  Precipitable water values of 2-2.25" exists here, per
GPS data.  Effective bulk shear of 25+ kts is moving into the
region.  CIN has yet to set in; ML CAPE is 1500-2500 J/kg.

The guidance appears to be missing the recent uptick, but is
aboard the idea of it happening in 2+ hours.  Given the parameters
in place, hourly rain amounts to 3" with local totals to 5" are
possible where cells train.  There appears to be better potential
for this overnight into Saturday morning due to the increase in
effective bulk shear.  This degree of rainfall would be most
problematic in urban areas.  Flash flooding occurrence is expected
to be isolated to widely scattered.

Roth

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...LIX...MOB...TAE...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON   31198581 30308588 30318671 30218754 30128851
            30328886 30438888 30708843 31098759