199
AWUS01 KWNH 222334
FFGMPD
MSZ000-LAZ000-ARZ000-TXZ000-230530-

Mesoscale Precipitation Discussion 0305
NWS Weather Prediction Center College Park MD
734 PM EDT Wed May 22 2024

Areas affected...east-central TX into southern AR/northern LA

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

Valid 222333Z - 230530Z

Summary...Areas of flash flooding are expected to continue from
east-central TX into northern LA/southern AR through 05Z. Intense
rainfall with hourly rainfall in excess of 3 in/hr will be
possible along with some isolated spots of additional rainfall
over 5 inches through 05Z.

Discussion...Radar and infrared satellite imagery from 23Z showed
two main clusters of convection of note with broadening regions of
cooling cloud tops over TX. The first was over central TX,
approaching the I-35 corridor between Temple and Waco with a
second near the Arklatex. Both regions have been associated with
gauge reports of ~2 inches of rain in 30 minutes. The environment
ahead of these storms contained ample shear (0-6 km bulk shear
over 50 kt), moisture (PWs approaching 2 inches) and instability
(MLCAPE over 3000 J/kg) to support intense organized convection
with southerly low level flow feeding storms as seen loops of
visible satellite imagery. Aloft, flow was rather diffluent aloft,
located on the southern edge of longwave troughing over the
western/central U.S.

Short term forecasts from the RAP showed southerly 925-850 mb mean
layer flow strengthening across I-45 (between Houston and Dallas)
through 06Z with speeds in excess of 30 kt at times. Further
organization is expected with a larger MCS anticipated into the
early overnight. Mean cell movement generally toward the east and
organized clusters toward the ESE will favor portions of
east-central TX into northern LA with the greatest potential for
heavy rain through 05Z due to repeating rounds with hourly
rainfall in excess of 3 inches at times. Some locations are
expected to receive additional rainfall totals over 5 inches with
areas of flash flooding likely to continue. Portions of this
region are still recovering from heavy rainfall received earlier
in the month and may be more susceptible to runoff from additional
heavy rain tonight.

Otto

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

ATTN...WFO...EWX...FWD...HGX...JAN...LCH...LZK...SHV...

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

LAT...LON   33239263 33109111 32209083 31199169 30569348
            30369484 30469697 31379752 32169728 32549652
            33119440