MESOSCALE PRECIPITATION DISCUSSION 0156
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
101 AM EDT SAT MAY 30 2015
 
AREAS AFFECTED...WEST-CENTRAL TO NORTH-CENTRAL TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 300455Z - 300730Z
 
SUMMARY...VERY INTENSE RAINFALL RATES POSSIBLE WITH SOME EXPANSION
OF CONVECTION OVER THE NEXT COUPLE OF HOURS.

DISCUSSION...RADAR AND SATELLITE IMAGERY SHOWS A SOUTHEAST
PROPAGATING MCS MOVING DOWN ACROSS WEST TX AT THIS TIME OUT AHEAD
OF A VERY WELL-DEFINED TROUGH DIGGING ACROSS SOUTHERN CO AND
NORTHERN NM. DIVERGENT FLOW ALOFT AHEAD OF THE TROUGH IS HELPING
TO PROVIDE LARGE SCALE ASCENT AS THE CONVECTION MOVES SOUTHEAST
INTO A VERY UNSTABLE AIRMASS POOLED ACROSS CENTRAL AND
WEST-CENTRAL TX. GOES-SOUNDER LI/S OF -10 TO -12 ARE DEPICTED
ACROSS THESE AREAS...AND AS ONE GOES FARTHER EAST...THE PWATS
INCREASE AS WELL.

THE CONVECTIVE LINE ITSELF SHOULD CONTINUE TO PROPAGATE GENERALLY
SOUTHEASTWARD OVER THE NEXT FEW HOURS...AND WILL BE PRODUCING
LOCALLY INTENSE RAINFALL RATES OF 1 TO 1.5 INCHES/HR. A LITTLE
FARTHER EAST...THERE IS SOME CONCERN FOR MORE DISCREET AND
SLOW-MOVING CELLS TO FORM IN THE VICINITY OF A FRONT THAT IS
DRAPED WSW/ENE ACROSS THE WEST-CENTRAL AND NORTH-CENTRAL TX. 

MULTIPLE RUNS OF THE HRRR SUPPORT CONVECTION DEVELOPING FARTHER
EAST ALONG THIS FRONT OUT AHEAD OF THE AFOREMENTIONED MCS. THE
UPSTREAM ENERGY WILL FAVOR AN UPTICK IN LARGER SCALE ASCENT
OVERNIGHT...AND WITH SUCH INSTABILITY POOLED OVER CENTRAL TX
CURRENTLY...THERE SHOULD BE SOME EASTWARD EXPANSION OF
CONVECTION...WITH SOME VERY SLOW-MOVING CELLS GIVEN WEAK STEERING
FLOW AHEAD OF THE MCS. THE LATEST RADAR TRENDS CONFIRM THIS
BEHAVIOR WITH THE CELLS DEVELOPING JUST NORTH OF KDYS.

SLOW MOVEMENT AND INTENSE RAINFALL RATES WILL FOSTER AT LEAST SOME
POTENTIAL FOR FLASH FLOODING. GIVEN SUCH WET CONDITIONS OF
LATE...ANY ADDITIONAL RAINFALL WILL PROMOTE RUNOFF PROBLEMS.

ORRISON

ATTN...WFO...FWD...LUB...MAF...SJT...

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

LAT...LON   33299874 32859794 32329821 32169870 31989964 
            31850010 31700155 31900218 32170227 32580207 
            33030122 33279987