MESOSCALE PRECIPITATION DISCUSSION 0069
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1041 PM EDT SAT MAY 24 2014
 
AREAS AFFECTED...SOUTHWEST TO CENTRAL TX... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 250241Z - 250611Z
 
SUMMARY...FLASH FLOODING WILL REMAIN POSSIBLE DURING THE NEXT
COUPLE OF HOURS FROM SOUTH OF FORT STOCKTON NORTHEASTWARD TO NEAR
SAN ANGELO TX. CONTINUAL REGENERATION OF CONVECTION HAS BEEN
OBSERVED ALONG THE SOUTHWESTERN FLANK OF AN OLD OUTFLOW BOUNDARY.
HEAVY RAINFALL OCCURRING DURING THE PAST FEW HOURS WILL MAKE
CONDITIONS MORE FAVORABLE FOR FLASH FLOODING THROUGH AT LEAST 05Z. 

DISCUSSION...DURING THE PAST SEVERAL HOURS...NUMEROUS CELLS WHICH
DEVELOPED IN THE VICINITY OF THE BIG BEND HAVE INTERACTED WITH A
REMNANT OUTFLOW BOUNDARY LEFT FROM AN MCC EARLIER IN THE DAY. THE
SOUTHWESTERN PERIPHERY OF THIS BOUNDARY HAS BECOME THE FOCAL POINT
FOR RENEWED CONVECTION WITH HIGH RAINFALL RATES OBSERVED. DOPPLER
RADAR AND IR SATELLITE SHOWED VERY LITTLE MOVEMENT IN THIS AXIS OF
DEEP CONVECTION WITH CLOUD TOP TEMPERATURES GENERALLY REMAINING IN
THE -70 TO -75 C RANGE. EFFICIENT HEAVY RAINFALL PRODUCTION HAS
BEEN OBSERVED BASED ON 00Z SOUNDINGS SHOWING A WARM CLOUD LAYER
EXTENDING UP TO OVER 11000 FT. WHILE THE REGION BEING AFFECTED IS
IN A VOID FOR RAIN GAUGE DATA...DOPPLER RADAR ESTIMATES HAVE SHOWN
A WIDESPREAD AXIS OF 2 TO 4 INCHES OF RAINFALL WITH POCKETS OF
OVER 5 INCHES. THESE AMOUNTS MAY BE A TAD HIGH GIVEN POSSIBLE HAIL
CONTAMINATION. LOCAL 3-HR FFG VALUES HAVE BEEN EXCEEDED ALTHOUGH
THERE HAVE BEEN NO REPORTS OF FLASH FLOODING THUS FAR.

THE CONVECTION-ALLOWING MODELS REMAIN AT ODDS WITH THE CURRENT
EVOLUTION OF THIS SYSTEM. THE 22Z HRRR WAS PROBABLY THE CLOSEST AT
RESOLVING THE PRECIPITATION AXIS WITH A FORECAST INDICATING THE
TRAINING COULD OCCUR FOR ANOTHER COUPLE OF HOURS. THE 22Z HRRR
SUGGESTED SOME INVIGORATION OF THIS STALLED BOUNDARY MAY OCCUR
FROM UPSTREAM CONVECTION EMANATING FROM THE SOUTHERN ROCKIES LATER
IN THE NIGHT. FOR NOW...THE 01Z RAP SHOWS THE AIR MASS FEEDING
INTO MPD AREA IS UNCAPPED WITH MLCAPE VALUES EXCEEDING 2000 J/KG.
ADDITIONALLY...00Z SOUNDINGS INDICATE THE ATMOSPHERE HAS FURTHER
MOISTENED WITH LOCAL VWP PROFILES SHOWING A SLIGHT SPIKE IN THE
LOW-LEVEL INFLOW WITH VALUES NEARING 30 KTS AT 3000 TO 5000 FT.
FEEL FLASH FLOODING WILL REMAIN POSSIBLE WITH THE AREA BEING
REASSESSED DURING THE NIGHT.


RUBIN-OSTER

ATTN...WFO...FWD...OUN...EWX...SJT...LUB...MAF...

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

LAT...LON   30530319 31380259 32050177 32960070 33459975 33059883
            32189864 31559908 31070009 29880207 30530319