MESOSCALE DISCUSSION 0646
   NWS STORM PREDICTION CENTER NORMAN OK
   0524 PM CDT WED MAY 15 2013
   
   AREAS AFFECTED...EDWARDS PLATEAU AND WEST/SOUTH-CENTRAL TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 152224Z - 160100Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...SEVERE TSTM POTENTIAL MAY INCREASE THROUGH EARLY EVENING
   ACROSS THE EDWARDS PLATEAU VICINITY/WEST-CENTRAL TX AND PERHAPS
   SOUTH-CENTRAL TX...WITH LARGE HAIL AS THE PRIMARY HAZARD. A DAMAGING
   WIND THREAT COULD MATERIALIZE AS WELL THIS EVENING.
   
   DISCUSSION...PER VISIBLE SATELLITE...CU FIELD HAS DEEPENED A DEGREE
   OVER THE PAST 1-2 HR ACROSS WEST-CENTRAL TX IN GENERAL VICINITY OF A
   BROWNWOOD TO JUNCTION TX CORRIDOR...WITH OTHER HIGHER-BASED CU
   EVIDENT ACROSS SOUTHWEST TX FROM BETWEEN LUBBOCK-MIDLAND SOUTHWARD
   TO EAST OF FORT STOCKTON/NEAR THE INTERNATIONAL BORDER NEAR
   SANDERSON. HEATING/MIXING ASIDE...THE HIGH-BASED CU DEVELOPMENT MAY
   BE ENHANCED BY A VORTICITY MAXIMA/JET STREAK PIVOTING SOUTHEASTWARD
   OVER THE REGION AS PER WATER VAPOR IMAGERY/REGIONAL DERIVED WIND
   DATA. SIMILAR TO SOME GUIDANCE SUCH AS THE 18Z NAM AND HIGH-RES
   WRF-NMM/WRF-NSSL...IT IS POSSIBLE THAT STRONG/SEVERE TSTM
   DEVELOPMENT MAY OCCUR ACROSS THE EDWARDS PLATEAU AND OTHER PARTS OF
   WEST-CENTRAL/SOUTH-CENTRAL TX BY EARLY THIS EVENING AS THE
   AFOREMENTIONED UPSTREAM ASCENT OVERSPREADS THE SOMEWHAT RICHER
   LOW-LEVEL MOISTURE. WHILE THE CU FIELD APPEARS RELATIVELY SUPPRESSED
   WEST OF THE RIO GRANDE NEAR/SOUTH OF DEL RIO...A STORM OR TWO
   DEVELOPING/CROSSING THE BORDER MAY ALSO BE POSSIBLE.
   REGARDLESS...STEEP LAPSE RATES/MODERATE INSTABILITY AND 40+ KT OF
   EFFECTIVE SHEAR WILL SUPPORT SUPERCELLS CAPABLE OF MAINLY LARGE
   HAIL...ALTHOUGH SOME MCS-TYPE DEVELOPMENT COULD MATERIALIZE LATER
   THIS EVENING WITH MORE OF A DAMAGING WIND THREAT.
   
   ..GUYER/CORFIDI.. 05/15/2013
   
   
   ATTN...WFO...FWD...EWX...SJT...
   
   LAT...LON   29870091 31100035 31289850 30319828 28480017 29870091