337
AWUS01 KWNH 281903
FFGMPD
LAZ000-ARZ000-TXZ000-OKZ000-290000-

Mesoscale Precipitation Discussion 1021
NWS Weather Prediction Center College Park MD
303 PM EDT Thu Aug 28 2025

Areas affected...in and around ArkLaTex

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

Valid 281900Z - 290000Z

SUMMARY...A few areas of isolated flash flooding will be possible
from southeastern OK/northeastern TX into southern AR and northern
LA through 00Z. Localized instances of training should support
hourly rainfall of 1 to 2 inches with spotty hourly totals of 2 to
3 inches.

DISCUSSION...Radar imagery from 1830Z showed broken coverage of
thunderstorms extending from east-central OK into central AR, with
a reduction in rainfall intensity and training axes over the past
couple of hours, partially tied to a weakened low level jet. There
were embedded mesoscale circulations noted within the broader
precipitation shield, located out ahead of a low to mid-level
shortwave located near the MO/KS/AR/OK 4-state junction,
translating downstream. This region of convection was located to
the north of a well-defined stationary front, enhanced by
differential heating, which extended WNW to ESE from the Red River
Valley into southern MS. Low level flow of 10-20 kt was in place
over northern TX into northwestern LA via VAD wind plots,
supporting overrunning of the front with cells moving
quasi-parallel to the boundary toward the ESE, allowing for
localized training and repeating. Aloft, flow was diffluent,
aiding in vertical ascent across the ArkLaTx region.

Robust surface heating to the south of the front was aiding in a
sharp instability gradient with 1500+ J/kg MLCAPE from far
southeastern OK into eastern TX and central LA and PWATs were
close to 2 inches in and around the ArkLaTex via 18Z SPC
mesoanalysis data. Additional thunderstorms are expected to form
near the frontal boundary over the next 2-4 hours with a general
movement of cells off toward the ESE. While coverage of these
additional cells remains uncertain, ongoing upstream convection
over OK and AR should continue while advancing toward the
SE/ESE...out ahead of the upstream shortwave. Alignment of
boundaries and the mean steering flow will likely support a few
areas of at least brief training and 1 to 2 inches of rain within
an hour. However, higher hourly rainfall totals cannot be ruled
out and may contribute to localized areas of flash flooding where
training is able to persist for 1-2 hours.

A negative to flash flood potential is that most of the outlooked
area has received below average rainfall over the past 1-2 weeks
leading to high flash flood guidance values of 3 to 5+ inches in 3
hours. Therefore, the greatest flash flood risk will likely reside
within urban areas or other locations with poor drainage.

Otto

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

ATTN...WFO...FWD...JAN...LCH...LZK...OUN...SHV...TSA...

ATTN...RFC...FWR...ORN...TUA...NWC...

LAT...LON   35159452 34899348 34149235 32749166 31129242
            31559426 32859630 34169663 34969591