Mesoscale Precipitation Discussion 0068
NWS Weather Prediction Center College Park MD
1008 PM EDT Sat Mar 15 2025

Areas affected...east-central Alabama into
west-central/northwestern Georgia

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

Valid 160207Z - 160600Z

Summary...A cluster of intense convection was producing areas of
1-2.5 inch/hr rain rates just south of the Birmingham Metro area.
Some concern exists that this activity could persist eastward,
eventually reaching the Atlanta Metro area through 04Z/midnight
EDT.

Discussion...Deep, intense convection has materialized throughout
a strongly sheared, unstable warm sector across
central/southwestern Alabama today.  More recently, a cluster of
strong storms (including LEWPs/bows and trailing/training
convection) has produced a localized area of 1-2.5 inch/hr rain
rates just south of Birmingham over the past 1-2 hours.  These
rates were approaching FFG thresholds (generally in the 2-inch/hr
range), and areas of at least minor excessive runoff are apparent
given MRMS Flash responses across the region.

Some concern exists that this complex will persist northeastward,
likely crossing the AL/GA border region by 03Z and reaching
portions of the Atlanta Metro area through/after 04Z.  The extent
of the flash flood threat may be mitigated by weaker downstream
instability (upper 50s F surface dewpoints contributing to only
around 500 J/kg MUCAPE), which could weaken updraft intensity. 
However, current convective organization and strong shear should
maintain heavier downpours downstream into northwestern Georgia
and result in at least a few areas of 1 inch/hr rainfall rates -
potentially affecting populated areas such as Atlanta Metro. 
Given the scenario, at least an isolated flash flood threat should
evolve with this convective cluster through 06Z.

Cook

ATTN...WFO...BMX...FFC...HUN...

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

LAT...LON   34518516 34418416 33868353 33298349 32998378
            32578531 32368759 33128757 34098620