MESOSCALE PRECIPITATION DISCUSSION 0072
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
654 PM EDT MON MAR 26 2018

AREAS AFFECTED...NORTH TEXAS INTO SOUTHERN AND CENTRAL OKLAHOMA

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

VALID 262254Z - 270445Z

SUMMARY...THERE IS AN INCREASING THREAT OF FLASH FLOODING FROM
PARTS OF NORTH TEXAS INTO SOUTHERN AND CENTRAL OKLAHOMA THIS
EVENING.  FLASH FLOOD GUIDANCE IS RATHER HIGH BUT STORM MOTION AND
THE MEAN FLOW ARE FORECAST TO BECOME ALIGNED WHICH SUGGESTS
POTENTIAL FOR TRAINING OF CELLS AND THE RESULTING POSSIBILITY OF
FLASH FLOODING.

DISCUSSION...CONVECTION LATE THIS AFTERNOON AND EARLY EVENING WAS
MORE IN A MODE OF PRODUCING SEVERE WEATHER THAN FLASH FLOODING. 
HOWEVER...MOISTURE MOVING NORTHWARD AND INTERACTING WITH A DRY
LINE OUT TO THE WEST AND THE APPROACH OF A COLD FRONT LATER THIS
EVENING...COMBINED WITH SOUTH TO SOUTHWEST FLOW AT THE LOW LEVELS
AND INCREASING PRECIPITABLE WATER VALUES SOUTH OF THE FRONT WILL
SET THE STAGE FOR LOCALIZED HEAVY RAINFALL RATES AND
ACCUMULATIONS.  WITH CELL MOTION BEING CLOSE TO THE MEAN LOW LEVEL
FLOW...THERE SHOULD BE THE POTENTIAL FOR TRAINING OF CELLS. 

THE 20Z AND 21Z HRRR QPF PAINTS A STRIPE OF 1 TO 2 INCH AMOUNTS
INTO THE EVENING HOURS IN THE AXIS OF HIGHEST PRECIPITABLE WATER
VALUES AND THE BEST LOW LEVEL MOISTURE FLUX CONVERGENCE AHEAD OF
THE DRY LINE.  GIVEN THAT THIS IS CLOSE TO THE PLACEMENT OF THE
AFTERNOON CONVCETION...THINK THAT FLASH FLOODING WILL BE POSSIBLE
THROUGH AT LEAST 04Z DESPITE THE FACT THAT FLASH FLOOD GUIDANCE
WAS INITIALLY CLOSER TO 3 INCHES PER HOUR. 

AFTER 04Z...THE ARW/NMMB AND HRRR ALL BEGIN TO WEAKEN CONVECTION.

BANN

ATTN...WFO...FWD...OUN...SJT...TSA...

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

LAT...LON   35819639 35619547 34119690 33129790 32609887
            33149954 34499840