MESOSCALE PRECIPITATION DISCUSSION 0019
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
522 PM EST TUE FEB 20 2018

AREAS AFFECTED...NERN TX/SERN OK/WRN AR

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

VALID 202152Z - 210350Z

SUMMARY...A FLASH FLOOD THREAT WILL CONTINUE FOR PARTS OF NERN TX
INTO SERN OK/WRN AR THROUGH AT LEAST 04Z. ADDITIONAL RAINFALL
TOTALS THROUGH 04Z OF 3-5 INCHES WILL BE POSSIBLE ON A LOCALIZED
BASIS.

DISCUSSION...RADAR IMAGERY OVER THE PAST SEVERAL HOURS HAS SHOWN
LOOSELY ORGANIZED CONVECTION OCCURRING IN THE VICINITY OF THE DFW
METROPLEX...OUT AHEAD OF A STRONG COLD FRONT...WITH INDIVIDUAL
CELLS MOVING TOWARD THE NORTHEAST AT ROUGHLY 40 KT. THIS MOTION
WAS SIMILAR TO THE LOW LEVEL FLOW VIA AREA VAD WIND DATA. AT
21Z...THE COLD FRONT WAS LOCATED SWWD THROUGH SERN OK INTO N-CNTRL
TX BEFORE ARCING BACK NWWD INTO THE TX PANHANDLE. THERE WAS A
TEMPORARY LULL IN PRECIPITATION BETWEEN THE LOOSELY ORGANIZED
CONVECTION MENTIONED EARLIER AND THE COLD FRONT WHICH WAS CROSSING
FWD AT 2130Z.

THE POTENTIAL FOR TRAINING CONVECTION IS STILL IN PLACE AHEAD OF
THE COLD FRONT FROM SOUTH OF THE DFW METROPLEX INTO AND ACROSS THE
RED RIVER INTO WRN AR OVER THE NEXT FEW HOURS. UPPER LEVEL
DIVERGENCE AND DIFFLUENCE ARE STILL IN PLACE OVER THE ARKLATEX
ALONG WITH DEWPOINTS IN THE MID TO UPPER 60S IN A FEW
PLACES...SUPPORTING ESTIMATED MLCAPE OF 500-1000 J/KG VIA THE
LATEST SPC MESOANALYSIS PAGE AHEAD OF THE COLD FRONT OVER
N-CNTRL/NERN TX.

OVER THE NEXT FEW HOURS...THE POTENTIAL FOR TRAINING HEAVY RAIN
HAS BEEN SUPPORTED IN RECENT RUNS OF THE HRRR AS WELL AS A
MAJORITY OF 12Z HI-RES GUIDANCE AND THE 18Z NAM-NEST FROM
LOCATIONS SOUTH/SOUTHEAST OF THE DFW METROPLEX INTO AND ACROSS THE
ARKLATEX. RAINFALL POTENTIAL OF 3-5 INCHES WILL BE POSSIBLE WITH
RAINFALL RATES OF 1.5 TO 2.5 IN/HR WHERE IDEAL ECHO TRAINING
OCCURS. COVERAGE OF THE 3-5 INCH TOTALS SHOULD BE LIMITED TO ONE
OR TWO LOCATIONS AT BEST.

OTTO

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

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

LAT...LON   35439426 35399353 34539325 33059402 31879539
            31529648 31729723 32339742 33059699 34349559