Subj : MESO: Nws Weather Prediction Center College Park Md
To   : wx-storm@lists.illinois.edu
From : COD Weather Processor
Date : Thu Nov 20 2025 16:53:30

AWUS01 KWNH 201653
FFGMPD
TXZ000-OKZ000-202230-

Mesoscale Precipitation Discussion 1236
NWS Weather Prediction Center College Park MD
1152 AM EST Thu Nov 20 2025

Areas affected...North TX into southwest OK

Concerning...Heavy rainfall...Flash flooding likely

Valid 201650Z - 202230Z

Summary...Additional rainfall of 1.5-3.0" (and locally higher) is
likely to result in scattered instances of flash flooding (and may
be locally significant).

Discussion...Low-level convergence upstream (southwest) of the DFW
metro has gradually consolidated a SSE to NNW training segment of
convection across portions of North TX with hourly totals now
approaching 2"/hr (per MRMS estimates). This line of showers and
thunderstorms is occurring along a ThetaE gradient well to the
east of the primary front (near the Rolling Plains and Cap Rock
south of the TX Panhandle) with precipitable water values of
1.5-1.7" (near record values, and well above the FWD 90th
percentile of ~1.2"), ML CAPE of 500-750 J/kg, and substantial
deep layer shear of 45-55 kts. As southerly low-level moisture
transport has recently ramped up, expect a period of several
several more hours of off and on heavy rainfall (with an even more
impressive train of showers is ongoing farther southwest over the
TX Hill Country, likely to move into the region while still
possibly maintaining 2-3"/hr rainfall rates).

The bulk of the hi-res guidance suggests an addition 1.5-3.0" of
rainfall over the next 3-6 hours (per 12z HREF probability matched
mean QPF) with the potential for localized 3" exceedance (per
40-km HREF >3" probs of 20-40%). With a narrow swath of 2-4" of
rainfall already having fallen over the past 6-12 hours (per NSSL
estimates), Flash Flood Guidance (FFG) are as low as 1.5-2.5" (and
even lower to the northwest of the metro area where the maximum
rainfall occured). Given these wet antecedent conditions and the
potential for additional significant heavy rainfall, scattered
instances of flash flooding are likely (and may locally be
significant, particularly across more sensitive urbanized terrain
and where streamflows are already elevated).

Churchill

....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!4irV483kYzdvk4QIYc2rRMeSYNgBQuyC8Mbjbl2gVhfVg5U5hcn2wKp_0KEqSN__j6v1=
gifA8jUNzsMY1UilaXWyX64$  for graphic product...

ATTN...WFO...FWD...OUN...SHV...TSA...

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

LAT...LON   34779506 34749469 34609448 34149451 33739464=20
            33489482 33219549 32879604 32429662 32159723=20
            32019790 32539822 32949780 33239739 33529712=20
            33869700 34159660 34509605 34679554=20

=3D =3D =3D
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