MESOSCALE PRECIPITATION DISCUSSION 0104
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
148 PM EDT TUE MAY 19 2015
 
AREAS AFFECTED...WRN OK...SRN OK...N TX...TX PANHANDLE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 191747Z - 192247Z
 
SUMMARY...A PROLONGED PERIOD OF SYNOPTIC ASCENT WILL BE FOCUSED IN
A ZONE NORTH AND SOUTH OF A WARM FRONT. RAIN RATES AND INSTANCES
OF TRAINING CONVECTION ARE EXPECTED TO INCREASE THIS AFTERNOON.
FLASH FLOODING IS POSSIBLE.

DISCUSSION...THE RAP AGREES WITH OTHER GUIDANCE IN PRODUCING LARGE
SCALE ASCENT OVER WRN OK / NW TX FOR THE DURATION OF THE AFTERNOON
AND EARLY EVENING. AT 1730Z DEEP CONVECTION WAS LOCATED PRIMARILY
NORTH OF A SURFACE WARM FRONT ANALYZED NEAR THE RED RIVER. UPPER
DIFLUENCE WILL BE SUPERIMPOSED ON MOST UNSTABLE CAPE VALUES
CLIMBING TO 500-1500 J/KG NORTH OF THE FRONT...SUPPORTING
WIDESPREAD CONVECTION. FARTHER SOUTH...SOME DEVELOPMENT INTO THE
WARM SECTOR...WHERE SFC-BASED CAPE WILL EXCEED 3000 J/KG...APPEARS
LIKELY GIVEN THE QUALITY OF MOISTURE AND ARRIVAL OF WEAK HEIGHT
FALLS. 

WITH STRONG WIND FIELDS COMING INTO PLACE AND A VARIETY OF STORM
MODES POSSIBLE...THE FLASH FLOOD RISK IS NOT ESPECIALLY FOCUSED.
THE CONCERN...HOWEVER...IS A BROAD WARM SECTOR...PERSISTENT AND
WELL-TIMED LIFT...AND TRANSPORT OF RICH GULF MOISTURE WITH PW
VALUES UP TO 1.7" OR AROUND 2.5 STANDARD DEVIATIONS FROM
CLIMATOLOGY. RAINFALL INTENSITY SHOULD INCREASE AS CAPE INCREASES.
CONVECTION WHICH MAY BECOME INCREASINGLY SURFACE BASED COULD TAKE
ON DEVIANT AND SLOWER MOTION...AND THE BROAD SOUTHERLY LOW LEVEL
WINDS WILL ALLOW FOR LOCAL TRAINING ON 1 TO 2 HOUR TIME SCALES.  

A COMBINATION OF THE 12Z WRF-ARW...NSSL WRF...AND THE AVERAGE OF
EARLY MORNING HRRR RUNS WOULD SUGGEST SW-NE ORIENTED SWATHS OF
HEAVY RAINFALL...LOCALLY 2-3 INCHES THROUGH 00Z...ACROSS A REGION
WITH ALREADY SATURATED SOILS.

BURKE

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

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

LAT...LON   36609917 35959792 34659712 34059701 33469746 
            32720015 32900142 33730219 34690196 36010095 
            36570005