MESOSCALE DISCUSSION 0400
   NWS STORM PREDICTION CENTER NORMAN OK
   0617 PM CDT SUN APR 10 2011
   
   AREAS AFFECTED...CNTRL TX NEWD TO ERN OK/WRN AR
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 102317Z - 110015Z
   
   A RELATIVELY LARGE AREA FROM NEAR SAN ANGELO TX NEWD INTO TULSA OK
   IS BEING MONITORED FOR CONVECTIVE INITIATION AND A POTENTIAL WW.
   LATEST DETERMINISTIC/HI-RES MODELS SUGGEST ISOLATED STORMS
   DEVELOPING AROUND 00Z...WITH MORE WIDESPREAD COVERAGE POSSIBLE
   THEREAFTER.
   
   THE PRESENCE OF AN EML HAS WIDELY LIMITED CONVECTIVE DEVELOPMENT
   ACROSS THE SRN PLAINS THROUGH THE AFTERNOON. HOWEVER...THE APPROACH
   OF AN UPPER TROUGH AND ASSOCIATED COOLING ALOFT IN COMBINATION WITH
   ADEQUATE HEATING/MOISTENING OF LOW LEVELS HAS GRADUALLY BEEN ERODING
   CONVECTIVE INHIBITION...EVIDENCED BY AN EXPANSIVE CU FIELD THAT IS
   BEGINNING TO DEVELOP ALONG AN APPARENT WEAK COLD FRONT/DRYLINE. LOW
   LEVEL FORCING ALONG THIS FEATURE SHOULD BE SUFFICIENT FOR AT LEAST
   ISOLATED STORMS TO DEVELOP OVER THE NEXT FEW HOURS. STEEPER
   MID-LEVEL LAPSE RATES NEAR 8 C/KM AND SUFFICIENT CLOUD BEARING SHEAR
   SHOULD SUPPORT OCCASIONAL ROTATION AND LARGE HAIL FORMATION IN
   STORMS THAT CAN SUSTAIN A STRONGER UPDRAFT...WITH A RISK FOR DMGG
   WINDS AND PERHAPS AN ISOLATED TORNADO SHOULD MORE SURFACE-BASED
   CONVECTION BECOME APPARENT. RELATIVELY WEAK LOW LEVEL FLOW IN
   COMPARISON TO AREAS FARTHER N AND LARGE T/TD SPREADS MAY LIMIT A
   MORE WIDESPREAD TORNADO THREAT. COVERAGE OF STORMS IS EXPECTED TO
   INCREASE AFTER DARK IN ASSOCIATION WITH A STRENGTHENING LOW LEVEL
   JET...WITH SHEAR VECTORS PARALLEL TO THE DRYLINE/WEAK COLD FRONTAL
   SURGE LEADING TO A BROKEN LINE OF CONVECTION THAT WILL PROGRESS EWD
   WITH TIME.
   
   ..HURLBUT.. 04/10/2011
   
   
   ATTN...WFO...SGF...TSA...FWD...OUN...SJT...
   
   LAT...LON   36739430 34439587 31719895 30870071 31170106 32809872
               35189643 36439550 36919468 36739430