466
AWUS01 KWNH 210005
FFGMPD
TXZ000-OKZ000-210600-

Mesoscale Precipitation Discussion 1344
NWS Weather Prediction Center College Park MD
804 PM EDT Sun Sep 20 2026

Areas affected...central to northern TX into southeastern OK

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

Valid 210003Z - 210600Z

SUMMARY...Slow moving thunderstorms will maintain a localized
flash flood threat across central to northern TX into southeastern
OK for another 3-6 hours, Efficient rainfall production will
result in isolated hourly rainfall of 2-4 inches and storm totals
of 3 to 5+ inches.

DISCUSSION...2340Z satellite/radar imagery showed a broken axis of
thunderstorms extending from the TX Hill Country into northern TX
and far southeastern OK. Loops of infrared satellite imagery
showed cloud tops were warming to the south of the DFW Metroplex,
but areas of cooling continued over the Edwards Plateau and near
the Red River. These storms were forming within an axis of higher
PWs (1.8 to 2.1 inches) and MLCAPE of 1000-2000 J/kg via 23Z SPC
mesoanalysis data, located ahead of ah mid to upper-level trough
advancing east across the southern High Plains. Right-entrance
region upper level jet divergence and diffluent flow aloft were
aiding large scale lift over TX. Slow storm motions and efficient
rainfall production have produced hourly rainfall as high as 3-4
inches and 15-minute rainfall over 1 inch near Denison, just south
of the Red River ending ~2330Z.

Expectations are for somewhat chaotic storm motions to continue
with storm generated outflows igniting new development over the
next few hours. Some westward development may also occur in the
next few hours. The favorable environment will maintain the
potential for very high rates in excess of 3 inches in an hour at
times along with 15-minute rainfall over 1 inch. Overlap of these
higher rates with urban areas or sensitive terrain in the Hill
Country may result in localized areas of flash flooding. Storms
should gradually wind down through 06Z, related to increasing
convective inhibition and eastward advancement of the upper trough
into central and eastern TX later in the night.

Otto

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

ATTN...WFO...EWX...FWD...OUN...SJT...TSA...

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

LAT...LON   34279615 34159550 33409554 31269705 29819808
            29279920 29560037 30020069 30430074 30880070
            31340059 31940031 32230002 32639948 32959880
            33279816 33609750 34219674