MESOSCALE DISCUSSION 0473
   NWS STORM PREDICTION CENTER NORMAN OK
   0644 PM CDT SUN APR 26 2015

   AREAS AFFECTED...PARTS OF THE EDWARDS PLATEAU INTO ADJACENT PORTIONS
   OF THE RIO GRANDE VALLEY

   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

   VALID 262344Z - 270145Z

   PROBABILITY OF WATCH ISSUANCE...60 PERCENT

   SUMMARY...INCREASING STRONG/SEVERE STORM DEVELOPMENT IS EXPECTED
   DURING THE 01-03Z TIME FRAME...WITHIN A CORRIDOR SOUTH OF ONGOING
   STORMS NEAR BROWNWOOD...THROUGH THE EDWARDS PLATEAU AND ADJACENT RIO
   GRANDE VALLEY.

   DISCUSSION...BOUNDARY LAYER MOISTURE IS RETURNING NORTHWESTWARD ON
   UPSLOPE FLOW ACROSS THE HILL COUNTRY INTO THE EDWARDS PLATEAU.  THIS
   WILL CONTINUE INTO EARLY EVENING...WITH DESTABILIZATION BECOMING
   MAXIMIZED ALONG AN AXIS OF ONGOING STRONGER SURFACE HEATING INTO THE
   90S...FROM NORTHWEST OF DEL RIO TOWARD THE ABILENE AREA.

   AS CAPE BECOMES INCREASINGLY LARGE IN THE PRESENCE OF THERMODYNAMIC
   PROFILES CHARACTERIZED BY VERY STEEP LOW AND MID TROPOSPHERIC LAPSE
   RATES...POTENTIAL FOR INTENSE CONVECTIVE DEVELOPMENT IS EXPECTED TO
   INCREASE.  VARIOUS MODEL GUIDANCE... INCLUDING THE LATEST RAPID
   REFRESH/HIGH RESOLUTION RAPID REFRESH ...IS SUGGESTIVE THAT THIS
   COULD OCCUR BY THE 01-03Z TIME...AIDED BY INCREASING FORCING
   ASSOCIATED WITH THE SOUTHERN ROCKIES CLOSED LOW.  DEEP LAYER
   VERTICAL SHEAR BENEATH BROADLY CYCLONIC...50-70 KT 500 MB FLOW WILL
   BE SUPPORTIVE OF ORGANIZED CONVECTIVE DEVELOPMENT...INCLUDING
   SUPERCELLS.  LOW-LEVEL SHEAR MAY NOT BE PARTICULARLY STRONG...BUT
   STRONGEST ACTIVITY PROBABLY WILL BE ACCOMPANIED BY A RISK FOR SEVERE
   HAIL...SOME VERY LARGE...WITH AN INCREASING RISK FOR DAMAGING WIND
   GUSTS AS ACTIVITY BEGINS TO SPREAD EASTWARD LATER THIS EVENING.

   ..KERR/KERR.. 04/26/2015


   ATTN...WFO...FWD...EWX...SJT...

   LAT...LON   30910023 31639968 32139945 32139881 30659924 29800074
               30410102 30910023