MESOSCALE PRECIPITATION DISCUSSION 0640...CORRECTION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1024 AM EST THU NOV 05 2015
 
AREAS AFFECTED...ARKLATEX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 051519Z - 051819Z
 
SUMMARY...THUNDERSTORMS ARE BEGINNING TO FILL IN WITHIN THE
ARKLATEX REGION.  HOURLY RAIN RATES UP TO 1.5" COULD LEAD TO FLASH
FLOODING.

DISCUSSION...THUNDERSTORMS ARE DEVELOPING WITHIN A MOISTURE PLUME
ASSOCIATED WITH THE SUBTROPICAL JET, WITH CLOUD TOP COOLING SEEN
ON RECENT INFRARED IMAGERY.  HOURLY RAIN RATES RECENTLY INCREASED
TO 1" AN HOUR PER DUAL POL ESTIMATES.  MUCAPES ACROSS THE REGION
ARE SLOWLY INCREASING PER RECENT SPC MESOANALYSES, IN THE 500-1500
J/KG RANGE ACROSS NORTHEAST TX.  SLIGHTLY CONVERGENT INFLOW AT 850
HPA OF 30-40 KTS EXISTS PER VAD WIND PROFILES, NEAR THE MAGNITUDE
OF THE 850-400 HPA MEAN WIND.  DIRECTIONAL WIND SHEAR IS STRONGEST
IN THE LOW-LEVELS, WITH THE FLOW NEARLY UNIDIRECTIONAL OUT OF THE
SOUTHWEST ABOVE THE BOUNDARY LAYER.  PRECIPITABLE WATER VALUES OF
1.9-2.2" LIE HERE, WHICH IS 3+ SIGMAS ABOVE THE MEAN FOR EARLY
NOVEMBER.

AS A SUBTLE SHORTWAVE CROSSES THE CENTRAL TX/OK BORDER,
THUNDERSTORM CONVERGE SHOULD BECOME MORE NUMEROUS TO ITS SOUTHEAST
IN/NEAR THIS REGION OVER THE NEXT COUPLE HOURS, WITH INDIVIDUAL
STORMS MOVING NORTH-NORTHEAST AT 45 KTS.  SHOULD ANY CONVECTION
BECOME MORE ORGANIZED, IT WOULD TURN MORE NORTHEAST OR
EAST-NORTHEAST PARALLEL TO THE 1000-500 HPA THICKNESS PATTERN. 
THIS CONVECTION SHOULD REMAIN FOR A FEW HOURS AS LONG AS CIN
REMAINS ACROSS THE CLOUDY REGION -- PICKED A THREE HOUR WINDOW DUE
TO THIS CONCERN.  A SOUTHEAST-SHIFTED 00Z WRF4NSSL APPEARS BEST
FOR CONVECTIVE PLACEMENT/MAGNITUDE.  LOCAL AMOUNTS OF 2-4" ARE
POSSIBLE, WHICH COULD FALL QUICKLY WITHIN AREAS OF CELL TRAINING. 
THE COMBINATION OF INSTABILITY AND AVAILABLE MOISTURE COULD ALLOW
FOR HOURLY RAIN RATES UP TO 1.5" WHERE TRAINING IS BEST. 
GALVEZ-DAVISON INDEX VALUES OF NEAR 35 INDICATE A MARGINAL FLASH
FLOOD THREAT.  ALTHOUGH IT APPEARS TO BE A MARGINAL SET UP, FLASH
FLOODING IS POSSIBLE HERE.

ROTH

ATTN...WFO...FWD...LZK...SHV...TSA...

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

LAT...LON   34739408 33719378 32469446 32269536 33039557 
            33789530 34309500 
Á