126
AWUS01 KWNH 050209
FFGMPD
TXZ000-050508-
MESOSCALE PRECIPITATION DISCUSSION 0082
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1008 PM EDT SAT APR 04 2026
AREAS AFFECTED...DEEP SOUTH TEXAS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 050208Z - 050508Z
SUMMARY...A CLUSTER OF DEEP CONVECTION SHOULD EVENTUALLY SPREAD
1-2.5 INCH/HR RAIN RATES INTO MCALLEN, TX AND VICINITY THROUGH
04-05Z.
DISCUSSION...DEEP CONVECTION HAS BECOME INCREASINGLY ORGANIZED
ACROSS PRIMARY RURAL AREAS OF DEEP SOUTH TEXAS OVER THE AREA. THE
STORMS ARE FOCUSED ALONG AN INVERTED SURFACE TROUGH EXTENDING INTO
THE AREA FROM NORTHEASTERN MEXICO, WITH LIGHT SOUTHEASTERLY
LOW-LEVEL FLOW MAINTAINING A SURFACE AIRMASS CHARACTERIZED BY 80S
F SURFACE TEMPS/70S F DEWPOINTS INTO THAT AXIS. STORMS WERE
BECOMING MORE ORGANIZED AND DEVELOPING COLD POOLS/WEAK
SUPERCELLULAR STRUCTURES, WHICH ISN'T SURPRISING GIVEN DIRECTIONAL
SHEAR THROUGH THE TROPOSPHERE. SOUTHWARD PROPAGATION OF THIS
CLUSTER SHOULD SPREAD AREAS OF 1-2.5 INCH/HR RAIN RATES INTO THE
MCALLEN, TEXAS AREA AND VICINITY, WHERE URBANIZED SURFACES MAY
POSE A RISK OF FLASH FLOODING AS THE CELLS MOVE THROUGH.
THE OVERALL SYNOPTIC SCENARIO SUPPORTING HEAVY RAINFALL SHOULD
CHANGE LITTLE THROUGH 05Z OR SO AS THE WEAK INVERTED TROUGH
PERSISTS AND WEAK MID-LEVEL WAVES TRAVERSE THE AREA. THE
LONGEVITY OF CONVECTION ALONG THE RIO GRANDE IS A BIT UNCERTAIN
AND HIGHLY DEPENDENT ON THE LOCAL EVOLUTION OF CONVECTION IN THAT
AREA, WHICH SHOULD BE RELATIVELY SLOW GIVEN WEAK WIND FIELDS ALOFT.
COOK
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...BRO...
ATTN...RFC...FWR...NWC...
LAT...LON 26999850 26729741 25969739 26229887 26599905
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