MESOSCALE DISCUSSION 0508
   NWS STORM PREDICTION CENTER NORMAN OK
   0510 PM CDT THU APR 21 2011
   
   AREAS AFFECTED...TRANS-PECOS REGION AND THE ERN PERMIAN BASIN OF W
   TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 176...
   
   VALID 212210Z - 212315Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 176
   CONTINUES.
   
   VISIBLE SATELLITE TRENDS INDICATE A LONE RIGHT-MOVING SUPERCELL
   LOCATED 30 SE FST...WHILE IN RECENT SCANS AN AGITATED TOWERING CU
   FIELD HAS DEVELOPED NEAR THE DRYLINE-WARM FRONT INTERSECTION
   APPROXIMATELY 30 ENE BGS. THIS CONVECTION IS DEVELOPING WITHIN A
   HOT/RELATIVELY MOIST AIR MASS /WITH ML CAPE VALUES EXCEEDING 3000
   J/KG ACROSS SRN PORTIONS OF THE WATCH/. THE PRIMARY THREATS WITH
   THESE THUNDERSTORMS WILL CONTINUE TO BE STRONG WIND GUSTS AND VERY
   LARGE HAIL...GIVEN THE PRESENCE OF A HOT/WELL-MIXED BOUNDARY LAYER
   AND STEEP MIDLEVEL LAPSE RATES. LARGE SFC T-TD SPREADS /30-40 DEG F/
   SHOULD TEND TO LIMIT THE THREAT FOR TORNADOES...BUT WITH FAVORABLE
   VEERING LOW-LEVEL SHEAR PROFILES THE POTENTIAL FOR A ROGUE TORNADO
   CANNOT BE RULED OUT. WEAK DEEP-LAYER FORCING AND THE PRESENCE OF A
   CAPPING INVERSION ABOVE 850 MB SHOULD CONTINUE TO FAVOR DISCRETE
   CONVECTIVE MODE.
   
   ..ROGERS.. 04/21/2011
   
   
   ATTN...WFO...OUN...EWX...SJT...LUB...MAF...
   
   LAT...LON   29740113 29740329 30490305 31430229 32930141 33260108
               33500009 33379947 32959913 29740113