MESOSCALE PRECIPITATION DISCUSSION 0110
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
313 AM EDT TUE APR 11 2017

AREAS AFFECTED...S-CNTRL TO E-CNTRL TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 110709Z - 111230Z

SUMMARY...FLASH FLOOD THREAT WILL LINGER THROUGH EARLY MORNING
WITH EXPECTED UPTICK IN HEAVY RAIN COVERAGE ACROSS THE SRN EDWARDS
PLATEAU...AND WITH GRADUAL SEWD SHIFTING OF THE ONGOING ACTIVITY
IN E-CNTRL TX. FLASH FLOODING SHOULD BE LOCALIZED TO A FEW
CORES...POSSIBLY REACHING 5+ INCHES THROUGH 12Z.

DISCUSSION...THE FLASH FLOOD THREAT THROUGH 06Z HAS BEEN CONFINED
TO A FEW 1-2 COUNTY-WIDE CORES OF 5+ INCHES VIA DUAL-POL ESTIMATES
DOTTING TX FROM THE SRN TRANS-PECOS INTO THE I-35 CORRIDOR BETWEEN
INJ AND TPL. WHILE COVERAGE HAS INCREASED SOUTH OF THE DFW
METROPLEX BETWEEN I-35 AND I-45...STORMS TO THE SOUTHWEST...OVER
THE EDWARDS PLATEAU...HAVE YET TO INCREASE IN COVERAGE AS SEVERAL
HI-RES MODELS HAVE BEEN SUGGESTING. HOWEVER...AS A WELL DEFINED
UPPER LEVEL TROUGH RAPIDLY APPROACHES FROM THE WEST...AS SEEN ON
WATER VAPOR IMAGERY...KEWX RADAR HAS SHOWN AN RECENT INCREASE IN
THUNDERSTORM ACTIVITY OVER KERR...BANDERA AND UVALDE COUNTIES.
INCREASING UPPER DIFFLUENCE AHEAD OF THE SHORTWAVE APPEARS TO BE
COMBINING WITH A BROAD RESERVOIR OF UNTAPPED INSTABILITY LOCATED
NORTHWEST OF SAT...WITH 1500-2500 J/KG MLCAPE PER A RECENT SPC
MESOANALYSIS. INCREASING COVERAGE OF CONVECTION IS EXPECTED OVER
THE NEXT 2-3 HOURS WITH POSSIBLE COLD POOL GENERATION AND
PROPAGATION TOWARD THE SOUTHEAST PER CORFIDI VECTORS.

CONVECTIVE COVERAGE HAS BEEN MORE WIDESPREAD ACROSS PORTIONS OF
E-CNTRL TX WITH THE BEGINNINGS OF AN MCS FORMATION APPARENT AS OF
0630Z IN INFRARED SATELLITE IMAGERY. WHILE THE 06Z SPC
MESOANALYSIS PAGE SHOWED REDUCED INSTABILITY ACROSS THIS
REGION...A SLOW BUT STEADY SWD PUSH TO THE SYNOPTIC COLD
FRONT...INCREASING UPPER DIFFLUENCE AHEAD OF THE AFOREMENTIONED
SHORTWAVE AND CONTINUED ADVECTION OF LOW LEVEL MOISTURE VIA 20-30
KT 850 MB FLOW IS EXPECTED TO SUSTAIN HEAVY RAIN RATES OVER THE
NEXT FEW HOURS WITH POSSIBLE WEAKENING TOWARD 12Z WITH REDUCING
INSTABILITY TOWARD E TEXAS...ESPECIALLY IF CONVECTION BECOMES
BETTER DEVELOPED ACROSS S-CNTRL TX. 1-3 INCHES WILL BE POSSIBLE
ACROSS A BROAD REGION OF THE MPD THREAT AREA...WITH LOCALIZED
MAXIMA IN EXCESS OF 5 INCHES POSSIBLE THROUGH 13Z.

OTTO

ATTN...WFO...CRP...EWX...FWD...HGX...

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

LAT...LON   31559650 31509520 30749495 30229569 29319693
            28599841 28580027 29400075 30049940 31259737