171
AWUS01 KWNH 150507
FFGMPD
TNZ000-ALZ000-MSZ000-151105-

Mesoscale Precipitation Discussion 1012
NWS Weather Prediction Center College Park MD
106 AM EDT Sun Sep 15 2024

Areas affected...Central to Northwest AL...Far Northeast MS

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

Valid 150505Z - 151105Z

SUMMARY...Heavy showers and thunderstorms are expected to impact
areas of central to northwest AL and possibly far northeast MS
going through dawn. Given the wet and locally saturated soil
conditions, the additional rains going through dawn may result in
some additional concerns for flash flooding.

DISCUSSION...The latest GOES-E IR satellite imagery shows a couple
of regional pockets of cooling convective cloud tops in
association with a broken axis of showers and thunderstorms
advancing southeast to northwest across areas of central to
northwest AL. The convection continues to focus around a broad
cyclonic circulation persisting over the Mid-South with an axis of
persistent moisture convergence and modest instability in place.
MUCAPE values are on the order of 250 to 500+ J/kg.

Rainfall rates have been seen increasing a bit over the last 1 to
2 hours with some of the convection that has been coming through
the Birmingham metropolitan area, and similar increases in
rainfall rates have been noted just west and south of Muscle
Shoals. The rates have locally increased to around 1 inch/hour and
there has been some additional cell-training concerns noted with
both the satellite and radar trends.

Notable differences exist in the 00Z HREF guidance with the
placement of the additional heavy rainfall threat overnight, but
the satellite and radar trends would suggest areas of central to
northwest AL, and perhaps far northeast MS will likely be the
primary corridor for the heaviest additional rainfall threat.
Given some of the cloud-top cooling and cell-training concerns,
additional rainfall totals going through dawn may reach as high as
2 to 3+ inches.

Given the wet and locally saturated soil conditions, these rains
may result in some additional flash flooding concerns going
through dawn.

Orrison

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

ATTN...WFO...BMX...HUN...MEG...OHX...

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

LAT...LON   35118795 34528698 33628630 33158654 33168741
            34118836 34848859