017
AWUS01 KWNH 280701
FFGMPD
MOZ000-ARZ000-TXZ000-OKZ000-281300-

Mesoscale Precipitation Discussion 0192
NWS Weather Prediction Center College Park MD
301 AM EDT Sun Apr 28 2024

Areas affected...Northern TX...Eastern OK...Western AR

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

Valid 280700Z - 281300Z

SUMMARY...Numerous to widespread areas of flash flooding are
likely over the next several hours for areas of northern TX
through eastern OK. Locally significant and life-threatening
impacts are expected.

DISCUSSION...The latest GOES-E IR satellite imagery in conjunction
with regional dual-pol radars show an elongated and strong QLCS
advancing gradually off to the east-northeast across northern TX
and eastern OK. The portion of the line that is generally
southwest of the Dallas-Fort Worth metroplex is advancing a bit
more progressively off to the east, but there is evidence in
surface observations of an area of low pressure riding up along
the convective line which is resulting in a wavy structure that
includes very strong convection over southern and eastern OK that
is tending to slow its forward propagation.

A nose of MLCAPE values on the order of 1500 to 2500 J/Kg remain
in place across the broader Red River Valley with the greatest
instability nosing up through northern TX and into southern OK.
There is a corridor of very strong and deep moisture convergence
across the region, with the latest CIRA-ALPW data reflecting
strengthening layered vapor transport (LVT) magnitudes all the way
up through 700mb. VWP data does indicate a 50 to 60+ kt low-level
jet in place and this coupled with the stronger forcing in
vicinity of the QLCS is resulting extremely heavy rainfall rates
that are in the 2 to 3+ inch/hour range.

The level of instability should tend to wane ever so gradually
across the Red River Valley over the next few hours heading
through sunrise, but the rainfall rates are expected to remain
quite high as the QLCS continues to gradually advance off to the
east-northeast early this morning. The biggest concern with the
early morning setup will be the localized persistence of these
extreme rainfall rates, as areas very slow cell-motions and
cell-training occur.

Expect areas locally in far northern TX, and south-central to
eastern OK, to see in excess of 5 inches of rain in as little as 2
to 3 hours. This will include areas along a line from near
Gainesville, TX northeastward up through McAlester and Stigler in
eastern OK. Areas farther south across northern TX, generally
south of the Dallas-Fort Worth metroplex will see lesser amounts,
but even here there may be locally as much as 2 to 4 inches of
rain through early this morning.

Numerous to widespread flash flooding is likely and some areas are
expected to see significant and life-threatening impacts.

Orrison

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

ATTN...WFO...FWD...LZK...OUN...SGF...SHV...SJT...TSA...

ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

LAT...LON   36639399 36039354 34889387 33369498 32029655
            31559784 31699875 32229891 33139841 34179745
            35289630 36479504