Flash Flood Guidance
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000
AWUS01 KWNH 300003
FFGMPD
LAZ000-ARZ000-TXZ000-OKZ000-300502-

MESOSCALE PRECIPITATION DISCUSSION 0152
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
802 PM EDT FRI APR 29 2016

AREAS AFFECTED...SE OKLAHOMA...SW ARKANSAS...NE TEXAS...EXT NW
LOUSIANA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 300002Z - 300502Z

SUMMARY...LARGE MCS WILL CONTINUE TO SUPPORT HEAVY RAINFALL
PRODUCTION ALONG EMBEDDED BOUNDARIES AND LIKELY OVER AREAS
AFFECTED THIS MORNING...LEADING TO LIKELY FLASH FLOODING ACROSS NE
TX/SW AR.

DISCUSSION...IR/VIS LOOP INDICATES LARGE MATURE MCS ACROSS THE
ARKLATX REGION BETWEEN THE BROAD SPLIT FLOW BETWEEN THE APEX OF
THE SUBTROPICAL JET SOUTH OF 30N AND THE 110-120 KT 3H POLAR JET
CYCLONICALLY CURVED ACRSS THE TX PANHANDLE.  THE MCS IS ALSO AT
THE NOSE OF DEEP INCREASINGLY CONFLUENT LOW LEVEL FLOW WITH A
BROAD SWATH OF 1.5" TPWS FROM DFW-SAT AXIS TO HOU-SHV AS FAR N/NE
AS SW AR...WITH MAX VALUES OVER 2" OVER NE TX.  MUDDLED SFC
BOUNDARIES DUE TO EARLY MORNING MCS AND OLD FRONTAL BOUNDARIES
CONTINUE TO FOCUS EMBEDDED DEEP CONVECTION WITH OVERSHOOTING TOPS
BREAKING OUT OVER THE TOP OF CIRRUS PARTICUALARLY AT THE BEST
CONVERGENCE AT THE SW EDGE IN NE TX NEAR KTYR/GGG.  MUCAPE
INSTABILTY WITHIN THIS DEEP MOISTURE AXIS/CONFLUENT FLOW ARE
FORECAST TO BE MAINTAIN EVEN RISE TO 1500-2000 J/KG NE TX INTO SW
TO CENTRAL AR NEARLY COINSIDENT WITH AREA OF LOWEST FFG VALUES
FROM THIS MORNINGS ROUND OF FLASH FLOODING AND AS SUCH WILL KEEP
UPDAFTS AND RAINFALL EFFICIENCY HIGH WITH RATES UP TO 2"/HR WITH
DEEPEST CONVECTION...AND GIVEN ORIENTATION TO THE FLOW...SOME CELL
TRAINING IS POSSIBLE.  HI-RES CAMS SUCH AS THE 18Z ESRL
HRRR...OPERATIONAL HRRR RUNS AND ARW CONTINUE TO PRODUCE A SWATH
OF 2-5" ACROSS NE TX/SW AR...MAKING FLASH FLOODING LIKELY.

GALLINA

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FWD...HGX...LZK...MEG...OUN...SHV...TSA...

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

LAT...LON   35609427 35519322 35389218 35139123 34629101
            34199153 33319259 32079332 31419484 31669564
            32789597 33609640 34459622 35289550 35479485




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