424
AWUS01 KWNH 141614
FFGMPD
GAZ000-ALZ000-MSZ000-142210-

Mesoscale Precipitation Discussion 1008
NWS Weather Prediction Center College Park MD
1213 PM EDT Sat Sep 14 2024

Areas affected...northeastern MS into AL and southwestern GA

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

Valid 141613Z - 142210Z

SUMMARY...Thunderstorms are likely to develop across northeastern
MS into AL and southwestern GA over the next 3-6 hours resulting
in possible flash flooding. Slow moving cells will likely produce
1-2 in/hr rainfall rates, which may overlap with areas that have
saturated soils.

DISCUSSION...1545Z radar imagery showed lingering rain showers
that formed along and east of an elevated convergence axis
centered near 925 mb that extended from the southern AL/GA border
into northwestern AL. Instability has lowered over northern AL
compared to earlier this morning which has allowed rainfall rates
to decrease, but small pockets of 1+ in/hr remained via MRMS
estimates from eastern AL into far southwestern GA. Visible
imagery showed the delineation between overcast skies with ongoing
showers in eastern AL and broken cloud cover to mostly clear skies
with new cumulus/shower development to the west/south over
central/southern AL into northeastern MS.

Low level easterly winds are expected to shift the boundary over
northern AL to the west through late afternoon while only slow
movement is expected to the south. Continued daytime heating
should allow weak MLCAPE values up to ~500 J/kg along the northern
MS/AL border while higher values in excess of 1000 J/kg expand
over central to southeastern AL given clearer skies as seen on
visible satellite imagery. A low to mid-level circulation tied to
former tropical cyclone Francine was located over northern MS,
allowing for a weakness in the steering flow from northwestern MS
into GA. Low level convergence is expected to redevelop a bit to
the southwest of its current position through the afternoon,
though RAP model forecasts are not as strong with the level of
convergence compared to earlier this morning. However, given the
high moisture environment and slow movement of cells atop
saturated soils across portions of the region, a couple of areas
of flash flooding may result. Expected rainfall rates of 1-2 in/hr
will likely become more numerous into the afternoon from the
northern MS/AL border into central/southeastern AL and
southwestern GA.

Otto

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

ATTN...WFO...BMX...FFC...HUN...JAN...MEG...MOB...TAE...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON   34998812 34768756 34318712 33128620 32228458
            31338442 31018547 31318652 32078766 32658837
            33188877 33858915 34588920 34888888