MESOSCALE PRECIPITATION DISCUSSION 0102
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1256 PM EDT FRI JUN 14 2013
 
AREAS AFFECTED...SOUTH-CENTRAL TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 141650Z - 142230Z
 
SUMMARY...SLOW-MOVING AND LOCALLY TRAINING CONVECTION WILL BE
CONDUCIVE FOR GENERATING VERY HEAVY RAINFALL AMOUNTS AND YIELDING
A HIGH THREAT FOR FLASH FLOODING THROUGH THE AFTERNOON.
 
DISCUSSION...LATEST RADAR IMAGERY SHOWS A GRADUALLY ORGANIZING
NW/SE ORIENTED BAND OF CONVECTION THAT IS SEEN SLOWLY LIFTING NWD
TOWARD PORTIONS OF THE BIG BEND AREA OF TX. IR SAT IMAGERY SHOWS
COLD TOPS ON THE ORDER OF -65C TO -70C...WITH THE TREND THE LAST
COUPLE HOURS OF ADDITIONAL COOLING WHICH IS INDICATIVE OF 
INTENSIFICATION. THE CONVECTION IS BEING FOSTERED BY AN ELONGATED
MID LVL TROUGH/SHEAR AXIS THAT EXTENDS FROM NRN MEXICO UP ACROSS
THE BIG BEND OF TX AND INTO PORTIONS OF W TX. ADDITIONALLY...THE
THERMODYNAMIC ENVIRONMENT IS VERY CONDUCIVE FOR DEVELOPING AND
SUSTAINABLE CONVECTION COURTESY OF A VERY MOIST SELY LOW LEVEL
FETCH WITH PWATS OF 2 TO 2.25 INCHES AND SBCAPE VALUES AOA 3000
J/KG ACROSS THE LOWER RIO GRANDE VALLEY.

EXPECTING THE CONVECTION OVER THE NEXT COUPLE OF HOURS TO CONTINUE
TO ORGANIZE AND EXPAND IN COVERAGE WITH A LIKELIHOOD FOR TRAINING
CONVECTION. VERY HEAVY RAINFALL RATES ARE EXPECTED...ON THE ORDER
OF 2 TO 4 INCHES/HR...AND THIS COUPLED WITH THE SLOW-MOVEMENT WILL
SUPPORT A LOCALLY SIGNIFICANT THREAT OF FLASH FLOODING. CANNOT
RULE OUT RAINFALL TOTALS ON THE ORDER OF 5 TO 10 INCHES AT LEAST
LOCALLY THIS AFTERNOON.

ORRISON

ATTN...WFO...CRP...EWX...BRO...SJT...MAF...

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

LAT...LON   31920141 30770010 29589917 28239852 27449842 27209893
            27329947 27920011 28760064 29920166 30730243 31640249
            31920141