AWUS01 KWNH 041722
FFGMPD
MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-042320-

Mesoscale Precipitation Discussion 1123
NWS Weather Prediction Center College Park MD
1221 PM EST Mon Nov 04 2024

Areas affected...Eastern OK...Northwest AR...Far Southeast
KS...Southwest MO

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

Valid 041720Z - 042320Z

SUMMARY...Heavy showers and thunderstorms will gradually become
more concentrated and organized by mid to late afternoon across
eastern OK which will also impact portions of northwest AR, far
southeast KS and southwest MO by this evening. Locally wet
antecedent conditions and the additional rainfall will likely
result in areas of flash flooding.

DISCUSSION...A strong deep layer trough and associated closed low
ejecting out of the southern Rockies will be interacting with a
very moist and increasingly unstable airmass pooling north across
the Red River Valley of the South, and will be setting the stage
for a more organized and concentrated convective outbreak by mid
to late afternoon across areas of eastern OK and eventually
advancing into far southeast KS, northwest AR and southwest MO by
early this evening. Many of these areas have already seen heavy
rainfall over the last couple of days, and the arrival of
additional rounds of strong convection and heavy rainfall rates
will promote a likelihood for seeing additional flash flooding
concerns.

The latest surface analysis shows a cold front gradually shifting
east across the Red River Valley of the South with a wave of low
pressure seen crossing through central OK. Meanwhile, a warm front
is noted out ahead of this stretching across eastern OK and into
northwest AR. MLCAPE values of 1500+ J/kg have already pooled up
across southeast OK and far western AR with 40 to 50+ kts of
effective bulk shear in place given the stronger wind fields
arriving ahead of the upper trough. Already the latest GOES-E
visible satellite imagery shows a substantial amount of cloud
street activity over eastern OK and this is suggestive of
increasing boundary layer instability with a strong low-level jet.

CIRA-ALPW data shows notably concentrated moisture in the
low-levels of the column with enhanced layered vapor transport
(LVT) seen extending up through northeast TX, eastern OK and
western AR. This is being facilitated by a southerly low-level jet
of 40 to 50 kts. This moisture transport coupled with the
instability and shear should favor an environment conducive for
enhanced rainfall rates.

As height falls associated with the upper trough arrive this
afternoon, a combination of DPVA/divergent flow aloft and the
favorable thermodynamic and kinematic environments will support
the development of more focused/organized convection which will
likely include embedded supercell activity. Rainfall rates will be
capable of reaching 1.5 to 2.5 inches/hour with the more organized
cells, and as convection grows upscale this afternoon and early
this evening, some additional storm totals may reach 2 to 4 inches
which is supported by the 12Z HREF guidance.

The wet antecedent conditions coupled with these additional rains
will likely result in more concerns for flash flooding by late
afternoon or early this evening.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!95vqJy86OmPuqhXcuLKln84-u1AkcPL89a_zxTnBQgrSnqC1KOAuuJfHhfXvAydRDGQd=
VD5W9jBLYO2dYZASnpyjkfU$  for graphic product...

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

ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC...

LAT...LON   37609449 37279352 36209347 34739408 33879507=20
            33969662 34659700 35739666 36809615 37439530=20
=20=20=20=20=20=20=20=20=20=20=20=20

=3D =3D =3D
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