MESOSCALE DISCUSSION 0359
   NWS STORM PREDICTION CENTER NORMAN OK
   0524 PM CDT SUN MAR 31 2013
   
   AREAS AFFECTED...PARTS OF S TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 73...74...
   
   VALID 312224Z - 010000Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   73...74...CONTINUES.
   
   SUMMARY...GREATEST RISK FOR LARGE HAIL WILL PERSIST WITH DISCRETE
   SUPERCELLS ACROSS THE WRN PORTION OF WW 73...WHICH SHOULD EVENTUALLY
   EVOLVE SEWD AND NECESSITATE A NEW WW ISSUANCE IN PARTS OF THE BRUSH
   COUNTY THIS EVENING. RISK FOR A COMBINATION OF MARGINALLY SEVERE
   HAIL/DAMAGING WINDS EXISTS INVOF GALVESTON BAY AREA BEFORE QLCS
   MOVES COMPLETELY OFFSHORE.
   
   DISCUSSION...CLUSTERS OF TSTMS CONTINUE TO EVOLVE SWD ALONG A
   SAGGING W/E-ORIENTED COMPOSITE COLD FRONT/OUTFLOW. THE MOST INTENSE
   REFLECTIVITY ALONG THE WRN PORTION OF A LARGE-SCALE QLCS WAS LOCATED
   INVOF GALVESTON BAY. THE PRIMARY LIMITING FACTOR TO MORE ROBUST
   SEVERE POTENTIAL HERE IS THE NEARLY PARALLEL NATURE OF THE
   DEEP-LAYER FLOW WITH THE ORIENTATION OF THE LINE ALONG WITH WEAK
   LOW-LEVEL WINDS AHEAD OF IT /AS SAMPLED BY THE HGX VWP/. STILL WITH
   INFLOW OF LOW TO MIDDLE 80S SURFACE TEMPERATURES TO THE SW AMIDST
   STEEP MID-LEVEL LAPSE RATES SUPPORTS A MIXED RISK OF MARGINALLY
   SEVERE HAIL/DAMAGING WINDS.
   
   FARTHER WEST...A PAIR OF SUPERCELLS ACROSS UVALDE AND KINNEY
   COUNTIES WILL CONTINUE TO POSE A PRIMARY RISK FOR LARGE HAIL
   /POSSIBLY SIGNIFICANT/ WITHIN A STRONGLY UNSTABLE AIR MASS. TSTM
   ACTIVITY HERE SHOULD CONTINUE TO EVOLVE SEWD JUST BEHIND THE
   COMPOSITE OUTFLOW/FRONT WHICH WILL PROBABLY LIMIT SEVERE WIND
   POTENTIAL TO SOME EXTENT SHORT-TERM. HOWEVER...GIVEN DOWNSTREAM CU
   AGITATION TO ZAVALA COUNTY...CONSOLIDATION OF UPDRAFTS IS POSSIBLE
   THAT MIGHT EVOLVE INTO AN ACCELERATING SEWD-CLUSTER INTO PARTS OF
   DEEP S TX LATER THIS EVENING.
   
   ..GRAMS.. 03/31/2013
   
   
   ATTN...WFO...LCH...HGX...CRP...EWX...
   
   LAT...LON   29939397 29489381 29069508 28929620 28489773 27999823
               27769902 27949988 28870053 29510102 29750088 29650014
               29479925 29419722 29639517 29939397