MESOSCALE PRECIPITATION DISCUSSION 0344
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
205 AM EDT MON JUN 13 2016
 
AREAS AFFECTED...CENTRAL AND NORTHEAST TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 130600Z - 131200Z
 
SUMMARY...CONVECTION TRAINING AND BACKBUILDING AHEAD OF A
PERSISTENT MCV  ALONG A MOISTURE/INSTABILITY AXIS COULD LEAD TO
SIGNIFICANT FLASH FLOODING DURING THE EARLY MORNING HOURS.

DISCUSSION...THE RADAR PRESENTATION OF THE CONVECTION OVER CENTRAL
AND NORTHEAST TX IS NOT AS IMPRESSIVE AS IT WAS SUNDAY EVENING.
THE LATEST RAP BASED INSTABILITY ANALYSIS SHOWED MLCAPE VALUES
HAVE DROPPED BELOW 1000 J/KG OVER THIS AREA...AS THE AIRMASS HAS
BEEN MUTED TO SOME DEGREE BY PREVIOUS CONVECTION. HOWEVER...THE IR
LOOP SHOWED VERY COLD CLOUD TOPS STILL IN PLACE (WITH TEMPERATURES
AS LOW AS -75 C). 

THE LONG-LIVED MCV IS STILL APPARENT ON THE KFWS/KGRK RADARS...AND
IT REMAINS A FOCUS FOR SOME OF THE REMAINING CONVECTION OVER
CENTRAL TX. THE REMAINING CONVECTION RESIDES ON THE NORTHEAST EDGE
OF THE DEEPER INSTABILITY LOCATED OVER SOUTH CENTRAL TX (WHERE
MLCAPE VALUES REMAIN BETWEEN 2000 AND 3000 J/KG). THE MOIST LOW
LEVEL INFLOW WILL CONTINUE TO TRANSPORT INSTABILITY NORTH AHEAD OF
THE MCV...AND LOW LEVEL CONVERGENT FLOW ALONG THE
MOISTURE/INSTABILITY AXIS SHOULD ALLOW CONVECTION TO REFIRE EARLY
THIS MORNING.

THERE IS A STRONG MODEL SIGNAL FOR AN AXIS OF HEAVY RAINFALL TO
OCCUR ALONG THE DEEP MOISTURE/INSTABILITY AXIS THROUGH 12Z. MOST
OF THE AVAILABLE HIGH RESOLUTION GUIDANCE (INCLUDING THE LATEST
HRRR/EXPERIMENTAL HRRR/00Z WRF ARW) INDICATE THE POTENTIAL FOR 4
TO 6 INCHES OF RAINFALL ALONG THIS AXIS...WITH LOCAL 8 INCH
AMOUNTS POSSIBLE. THESE RAINFALL AMOUNTS WOULD RESULT IN
SIGNIFICANT FLASH FLOODING.

THIS IS OF COURSE CONTINGENT ON THE CONVECTION REFIRING ALONG THE
AXIS AS DEPICTED BY THE HIGH RESOLUTION GUIDANCE. IF THE
CONVECTION IS SLOWER TO DEVELOP... THE RAINFALL AMOUNTS COULD BE
OVERDONE.

HAYES

ATTN...WFO...EWX...FWD...HGX...SHV...SJT...

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

LAT...LON   32849502 32809478 32119441 31639497 30969542 
            30469578 30139617 30189666 30349698 30769773 
            31069831 31129836 31459869 31829874 31929831 
            32009822 32259763 32539681 32699584 32809550