MESOSCALE DISCUSSION 1543
NWS STORM PREDICTION CENTER NORMAN OK
0314 PM CDT SUN JUL 22 2012
AREAS AFFECTED...CNTRL/SRN TX...FAR SERN NM
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 222014Z - 222245Z
PROBABILITY OF WATCH ISSUANCE...5 PERCENT
SUMMARY...A VERY ISOLATED THREAT FOR SVR WIND GUSTS WILL EXIST
ACROSS A BROAD AREA OF CNTRL/SRN TX INTO FAR SERN NM. THE SVR THREAT
WITH INDIVIDUAL STORMS SHOULD REMAIN BRIEF...WITH CONVECTION
REMAINING DISORGANIZED...AND THE ISSUANCE OF A WW IS NOT NEEDED.
DISCUSSION...ISOLATED TO LOCALLY SCATTERED THUNDERSTORMS ARE
ANTICIPATED INTO LATE AFTERNOON OWING TO DEEP BOUNDARY-LAYER
CIRCULATIONS ASSOCIATED WITH SFC TEMPERATURES IN THE 90S TO AROUND
100 DEGREES AMIDST PW VALUES OF 1.1 TO 1.8 INCHES PER GPS DATA. THIS
MOISTURE APPEARS TO BE ENHANCED INVOF TWO AXES: /1/ ONE AXIS LYING
ACROSS SW TX INTO CNTRL NM OVER THE ERN FRINGES OF A BROAD
SUBTROPICAL MOISTURE PLUME...AND /2/ ANOTHER AXIS ACROSS CNTRL/SERN
TX INVOF A MINOR IMPULSE TRAVERSING THE SRN FLANK OF A CNTRL CONUS
ANTICYCLONE. CONVECTION WILL CONTINUE THROUGH THE AFTERNOON OWING TO
ASCENT IN ASSOCIATION WITH /1/ THE IMPULSE.../2/ A SFC TROUGH LYING
FROM THE TX SOUTH PLAINS INTO N-CNTRL TX.../3/ SEA BREEZE BOUNDARIES
ALONG THE UPPER TX COASTAL PLAIN...AND /4/ DIFFERENTIAL HEATING
ZONES OVER THE FRINGES OF MULTI-LAYERED CLOUDS ACCOMPANYING THE
IMPULSE AND CONVECTION APPROACHING FROM SWRN LA.
MLCAPE VALUES OF 500-1500 J/KG WILL SUPPORT SOME VIGOROUS
UPDRAFT/DOWNDRAFTS...WITH STRONG WIND GUSTS THE MAIN CONCERN. GIVEN
DCAPE VALUES IN EXCESS OF 1000 J/KG AIDED BY STEEP LOW-LEVEL LAPSE
RATES...A VERY ISOLATED SVR THREAT MAY EVOLVE. HOWEVER...WEAK
LOW/MID-LEVEL FLOW PER AREA VWP/PROFILER DATA WILL FOSTER
DISORGANIZED/PULSE CONVECTION...WITH ANY SVR THREAT EXPECTED TO
REMAIN VERY ISOLATED.
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