847
AWUS01 KWNH 260332
FFGMPD
ARZ000-TXZ000-OKZ000-260930-
MESOSCALE PRECIPITATION DISCUSSION 0133
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1131 PM EDT SAT APR 25 2026
AREAS AFFECTED...NORTHERN TEXAS...SOUTH-CENTRAL TO SOUTHEAST
OKLAHOMA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY
VALID 260331Z - 260930Z
SUMMARY...SUPERCELLS AND MERGING CONVECTIVE CLUSTERS WILL CONTINUE
TO ORGANIZE AND PROPAGATE SOUTHEASTWARD OVERNIGHT. AN INCREASINGLY
FAVORABLE NOCTURNAL ENVIRONMENT WILL SUPPORT RAINFALL RATES OF 2+
INCHES/HOUR. WHILE ANTECEDENT CONDITIONS ARE RELATIVELY DRY,
INTENSE LOCALIZED RATES AND CELL-MERGERS MAY YIELD TOTALS OF 2 TO
4+ INCHES, POSING ESPECIALLY AN URBAN FLASH FLOOD THREAT.
DISCUSSION...GOES-E IR/WV SATELLITE IMAGERY AND RECENT
MESOANALYSIS SHOW A LOW-AMPLITUDE MID-LEVEL SHORTWAVE TROUGH OVER
THE PLAINS INTERACTING WITH A HIGHLY UNSTABLE AIRMASS ACROSS THE
RED RIVER VALLEY. A HIGHLY CONDUCIVE THERMODYNAMIC ENVIRONMENT IS
IN PLACE, CHARACTERIZED BY PWS OF ~1.5 INCHES, MLCAPE OF 2500-3500
J/KG, AND VERY STEEP MID-LEVEL LAPSE RATES (7.5-8 C/KM). THIS IS
FUELING ROBUST SUPERCELLULAR CONVECTION, AIDED BY DEEP-LAYER SHEAR
LOCALLY EXCEEDING 50 KTS. CONVECTION OVER NORTHERN TX REMAINS
LARGELY SURFACE-BASED WITHIN THE WARM SECTOR, WHILE ACTIVITY OVER
SOUTHERN OK IS SLIGHTLY ELEVATED, SUPPORTED BY A STATIONARY FRONT
AND 925 MB FRONTOGENESIS.
THROUGH THE OVERNIGHT HOURS, THE CURRENT 20 TO 30 KT LOW-LEVEL JET
IS FORECAST TO INTENSIFY, AND THIS NOCTURNAL ENHANCEMENT WILL
INCREASE WARM AIR ADVECTION AND MOISTURE TRANSPORT DIRECTLY INTO
THE RED RIVER VALLEY, PARTICULARLY TOWARD SOUTH-CENTRAL AND
SOUTHEAST OK. UPWIND PROPAGATION VECTORS ARE ALIGNED TO THE
SOUTHEAST, STRONGLY FAVORING THE GRADUAL UPSCALE GROWTH OF MERGING
SUPERCELLS INTO A FORWARD-PROPAGATING MCS.
THE 00Z HREF INDICATES A 20 TO 30 PERCENT PROBABILITY OF RAINFALL
RATES EXCEEDING 2 INCHES/HOUR WITHIN THE HEAVIEST CORES. STORM
TOTALS OF 2 TO 4 INCHES ARE EXPECTED, WITH LOCALLY HIGHER AMOUNTS
WHERE CELL-TRAINING OR COMPLEX MERGERS OCCUR. WHILE FLASH FLOOD
GUIDANCE (FFG) IS HIGHER ACROSS THIS CORRIDOR DUE TO DRIER
ANTECEDENT CONDITIONS, THE SHEER INTENSITY OF THE 2+ INCHES/HOUR
RATES WILL EASILY OUTPACE INFILTRATION, RESULTING IN ISOLATED TO
SCATTERED AREAS OF FLASH FLOODING, ESPECIALLY OVER ANY URBAN
FOOTPRINTS. THIS WILL INCLUDE PORTIONS OF THE DALLAS-FORT WORTH
METROPOLITAN AREA OVER THE NEXT 1 TO 2 HOURS IN PARTICULAR.
ORRISON
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...FWD...OUN...SHV...TSA...
ATTN...RFC...FWR...ORN...TUA...NWC...
LAT...LON 34429609 33999474 33359420 32639414 32009488
32039649 32519751 32969786 33759788 34269736
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