MESOSCALE PRECIPITATION DISCUSSION 0050
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
849 PM EDT MON MAY 12 2014
 
AREAS AFFECTED...EASTERN TX...WESTERN LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 130045Z - 130345Z
 
SUMMARY...SLOW-MOVING BAND OF INTENSE CONVECTION OVER EASTERN TX
WILL BE MERGING WITH CONVECTION OVER WESTERN LA OVER THE NEXT 2 TO
3 HOURS. FLASH FLOODING WILL BE POSSIBLE

DISCUSSION...THE SRN EXTENSION OF A LARGE QLCS IS SEEN SLOWLY
PUSHING SEWD THROUGH CNTRL AND NERN TX ATTM.
MEANWHILE...SLOW-MOVING MULTI-CELLULAR CONVECTION OVER WRN LA AND
PORTIONS OF FAR ERN TX IS SEEN LIFTING GRADUALLY NWWD. VERY HVY
RAINFALL RATES ARE GIVEN THE VERY MOIST/UNSTABLE ENVIRONMENT OVER
THE SRN PLAINS AND THE LWR MS VLY. LATEST SBCAPE VALUES ARE
LOCALLY OVER 3000 J/KG...AND GOES-SOUNDER PWATS ARE NOTED TO BE
BETWEEN 1.8 AND 2.0 INCHES.

OVER THE NEXT FEW HOURS...THE SRN TAIL OF THE QLCS INVOLVING ERN
TX WILL MERGE WITH THE CONVECTIVE CLUSTER OVER WRN LA...AND THE
RESULT IS EXPECTED TO BE A SHORT-TERM THREAT OF FLASH FLOODING DUE
TO VERY INTENSE RAINFALL RATES OVER A 1 TO 3 HR PERIOD. RAINFALL
RATES MAY APPROACH 3 INCHES/HR INVOF THE CELL MERGERS.

THE LATEST GLOBAL MODEL GUIDANCE AND TO A LESSER EXTENT THE HI-RES
MODELS ARE NOTABLY SLOW WITH THE QLCS EVOLUTION...AND ARE NOT
PARTICULARLY RELIABLE ATTM. THEY ARE NOT DEPICTING WHAT WILL BE AN
OBVIOUS CLUSTER OF CELL MERGERS INVOLVING THE QLCS EITHER.
NEVERTHELESS...BASED ON THE LATEST SAT/RADAR TRENDS...ORGANIZED
CONVECTION WILL CONTINUE TO PERSIST THROUGH THE EVENING...AND
FLASH FLOODING WILL BE POSSIBLE.

ORRISON

ATTN...WFO...LCH...SHV...HGX...FWD...

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

LAT...LON   30609368 30669442 30919527 31559579 32349495 32609486
            32799414 32579346 31989277 31299260 30709319 30609368