MESOSCALE PRECIPITATION DISCUSSION 0679
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
454 AM EST SUN DEC 13 2015
 
AREAS AFFECTED...ERN TX...SERN OK...WRN AR 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 130953Z - 131500Z
 
SUMMARY...HEAVY RAIN WILL CONTINUE OVER THE NEXT SEVERAL HOURS AS
A SQUALL LINE MOVES ACROSS ERN TX AND SERN OK. RAIN RATES IN THIS
CONVECTION ARE GENERALLY 0.5-1.0 IN/HR. GIVEN LOWERED FLASH FLOOD
GUIDANCE OVER MUCH OF THIS AREA FROM PREVIOUS RAINS...FLASH
FLOODING IS LIKELY. AN ADDITIONAL 1-2 INCHES OF RAIN ARE POSSIBLE
THROUGH 15Z.

DISCUSSION...A SQUALL LINE IS ONGOING EARLY THIS MORNING FROM ERN
TX INTO SERN OK. RAIN RATES HAVE INCREASED OVER THE PAST FEW HOURS
IN THIS SQUALL LINE AS UPPER-LEVEL FORCING HAS BECOME MORE
FAVORABLE AND THE LOW-LEVEL JET HAS STRENGTHENED TO 60-70 KT...IN
SPITE OF VERY LIMITED IN SPITE OF LIMITED INSTABILITY (MUCAPE
GENERALLY LESS THAN 500 J/KG). IMPRESSIVE PWAT VALUES FOR MID
DECEMBER...NEARING OR SURPASSING 2 IN. ARE PROMOTING HIGH
PRECIPITATION EFFICIENCY IN THIS AREA. HI-RES MODELS INDICATE THE
POTENTIAL FOR AN ADDITIONAL 1-2 INCHES OF RAIN OVER THIS AREA
THROUGH 15Z.

DUE TO EARLIER RAINS -- 1 HR FLASH FLOOD GUIDANCE HAS LOWERED TO
NEAR A HALF INCH OR LESS OVER PORTIONS OF THE OUTLINED AREA...THE
OBSERVED RAIN RATES OF 0.50-1.0 IN/HR IN THIS LINE SHOULD BE
SUFFICIENT TO PRODUCE FLASH FLOODING FOR SOME AREAS.

RYAN

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

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

LAT...LON   36439459 36229368 34869349 33589389 32869410 
            31489422 30499459 29969617 30479685 31659633 
            33429620 34329617 35549582 36249520