721
AWUS01 KWNH 281542
FFGMPD
ALZ000-MSZ000-LAZ000-ARZ000-282045-

Mesoscale Precipitation Discussion 1020
NWS Weather Prediction Center College Park MD
1142 AM EDT Thu Aug 28 2025

Areas affected...ArkLaMiss into central MS and far western AL

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

Valid 281540Z - 282045Z

SUMMARY...Heavy rainfall may result in localized areas of flash
flooding across central MS in a northwest to southeast fashion,
possibly impacting small portions of AR/LA and AL. Training of
thunderstorms will be capable of 1-2 in/hr rainfall rates. Mostly
dry antecedent conditions should limit the greatest flash flood
risk to urban areas or other locations with poor drainage.

DISCUSSION...Area radar imagery at 1530Z showed a NW to SE
oriented axis of showers and embedded thunderstorms from central
AR into central MS, with KDGX radar reflectivity/velocity data
indicating an MCV to the northeast of Jackson over Leake County.
Areas of heavy rainfall aligned with an elevated 925-850 mb
convergence axis which was oriented northwestward from the MCV
feature over central MS. Deeper layer steering flow oriented
quasi-parallel to the convergence axis has supported periods of
training over the past few hours with MRMS-derived hourly totals
peaking in the 1-2 inch range over the past couple of hours
(mostly in the vicinity of I-20).

Short term RAP forecasts show the MCV tracking ESE toward western
AL over the next 3-5 hours with the trailing convergence axis
remaining from southeastern AR into central MS with a slow
southward drift. While moisture is high (12Z JAN sounding with 2.0
inches), elevated instability is a bit lacking within the ongoing
precipitation axis at ~500 J/kg or less via 15Z SPC mesoanalysis
data, but instability is higher to the south and increasing with
daytime heating. Despite the weak instability, the potential will
exist for localized flash flooding over the next 3-5 hours from
training and 1-2 in/hr rain rates. Storm total rainfall of 2-3
inches will be possible over a relatively short period of time.

Otto

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

ATTN...WFO...BMX...JAN...LZK...MEG...MOB...

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

LAT...LON   34379117 34049017 33608941 33298862 32918793
            32268786 31558812 31348924 31759065 33319185