MESOSCALE PRECIPITATION DISCUSSION 0065
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1229 AM EDT SAT MAY 09 2015
 
AREAS AFFECTED...NRN TEXAS / SERN OKLAHOMA INTO WRN ARKANSAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 090428Z - 090958Z
 
SUMMARY...A CONTINUED INFLUX OF MOISTURE/INSTABILITY VIA THE LOW
LEVEL JET THROUGH EASTERN TEXAS IS EXPECTED TO PROLONG THE FLASH
FLOOD THREAT OVER THE NEXT SEVERAL HOURS FROM NRN TEXAS INTO SERN
OKLAHOMA AND WRN ARKANSAS.

DISCUSSION...AT 04Z...A LARGE...FORWARD PROPAGATING MCS CONTINUED
TO ADVANCE THROUGH ERN OKLAHOMA CONTAINING RAINFALL RATES
GENERALLY BETWEEN 1 TO 2 IN/HR WITHIN EMBEDDED STRONGER CORES. AN
EFFECTIVE FRONTAL BOUNDARY...ENHANCED BY RAIN COOLED
AIR...EXTENDED SOUTH OF THIS COMPLEX ACROSS THE RED RIVER JUST
EAST OF DUA...WSWWD TO RPH...DYS...TO MAF. CONVERGENCE ALONG THIS
BOUNDARY HAS BEEN ALLOWING STORMS TO DEVELOP IN A LINE...EXTENDING
SW OF THE MAIN OKLAHOMA MCS. 

00Z RAOBS CONFIRMED AMPLE INSTABILITY OF GREATER THAN 2000 J/KG
ACROSS CNTRL TEXAS WITH THE CORE OF THE LOW LEVEL JET ORIENTED
FROM NEAR DRT TO FWD...HELPING TO PUMP MOISTURE NNEWD THROUGH
CNTRL TEXAS. CURRENT GPS PRECIPITABLE WATER PLOTS SHOW 1.75 TO
2.00 INCHES FROM THE RIO GRANDE TO THE RED RIVER...NEAR THE 99TH
PERCENTILE FOR THE REGION.

THE GREATEST FLASH FLOOD THREAT IS EXPECTED TO BE NEAR THE
ARKLATEX AS HEAVY RAINFALL CORES REPEAT TOWARD THE EAST OVER
SATURATED SOILS FROM PRIOR HEAVY RAINFALL. THE MAGNITUDE OF THE
LOW LEVEL JET ACROSS ARKANSAS IS SOMEWHAT WEAKER THAN NRN
TEXAS...WHICH MAY DIMINISH THE FLASH FLOOD THREAT INTO CNTRL
ARKANSAS EARLY THIS MORNING. REPEATING CORES BUT WITH REDUCED
COVERAGE...ARE EXPECTED TO KEEP A THREAT FOR FLASH FLOODING JUST
NORTH OF I-20 INTO N-CNTRL TEXAS UNTIL AT LEAST 10Z.

OTTO

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

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

LAT...LON   35309357 35029305 34439257 33629268 33369322 
            33309403 33139626 32529857 32419980 32510012 
            32820021 33130012 33419965 33569848 33789777 
            34409676 34819604 35199503 35299420