MESOSCALE PRECIPITATION DISCUSSION 0661
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
155 AM EDT SAT SEP 10 2016
 
AREAS AFFECTED...SOUTHWEST OK...NORTHERN TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 100554Z - 101154Z
 
SUMMARY...AN ISOLATED FLASH FLOOD RISK MAY DEVELOP OVER THE NEXT
COUPLE HOURS AS CONVECTION EXPANDS ACROSS SOUTHERN OK AND NORTHERN
TX.

DISCUSSION...A MARGINAL FLASH FLOOD RISK MAY BE DEVELOPING TONIGHT
ACROSS SOUTHWEST OK INTO NORTH CENTRAL TX. RECENT RADAR AND IR
SATELLITE IMAGERY SHOW EXPANDING AND INTENSIFYING CONVECTION
ACROSS FAR SOUTHWEST OK AND ADJACENT AREAS OF TX OVER THE PAST
HOUR OR SO ALONG A SOUTHWARD MOVING COLD FRONT. 250 MB HEIGHTS
SHOW VERY DIVERGENT FLOW OVER THE AREA ON THE EDGE OF THE STRONG
UPPER JET TO THE NORTH. ALSO VAD WIND PROFILES AND RECENT RAP
ANALYSIS SHOW A CORRIDOR OF ENHANCED LOW LEVEL SOUTHERLY FLOW
ACROSS WEST TEXAS. THIS IS LIKELY INCREASING LOW LEVEL MOISTURE
FLUX INTO THE FRONT...AND FLOW PERPENDICULAR TO THE BOUNDARY IS
ALLOWING FOR BACKBUILDING NORTH OF THE SOUTHWARD SHIFTING FRONT.
CONVECTION IS EXPECTED TO CONTINUE TO BUILD SOUTHWEST ALONG THE
FRONT.

MAIN LIMITING FACTOR FOR FLASH FLOODING IS LIKELY THE FAST FORWARD
PROGRESSION OF THE FRONT...LIMITING THE DURATION OF TRAINING.
ALTHOUGH COULD STILL SEE SOME TOTALS AROUND 2-4"...WHICH COULD
RESULT IN AN ISOLATED FLASH FLOOD THREAT OVER THE NEXT SEVERAL
HOURS. THIS THREAT WILL BE LOCALLY ENHANCED WHERE CONVECTION IS
ABLE TO DEVELOP OUT AHEAD OF THE COLD FRONT...WHICH WOULD ADD TO
THE RAINFALL DURATION AS IT MERGES WITH THE COLD FRONTAL
CONVECTION. RECENT RUNS OF THE HRRR AND THE 0Z NSSL WRF APPEAR TO
HAVE A DECENT HANDLE ON THE EXPECTED EVOLUTION.

CHENARD

ATTN...WFO...AMA...FWD...LUB...MAF...OUN...SJT...

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

LAT...LON   34999756 34649713 32679751 31919869 32120187 
            32380255 32830257 33450184 33950126 34969979