MESOSCALE DISCUSSION 0543
   NWS STORM PREDICTION CENTER NORMAN OK
   0202 PM CDT MON APR 23 2007
   
   AREAS AFFECTED...SWRN KS SWD INTO THE ERN HALF OF THE TX
   PANHANDLE/WRN OK
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 231902Z - 232045Z
   
   CORRECTED FOR MISSING GRAPHIC
   
   SCATTERED TO ISOLATED SEVERE STORMS ARE FORECAST TO DEVELOP ACROSS
   THE SRN HIGH PLAINS ALONG/AHEAD OF THE DRYLINE LATER THIS AFTERNOON.
    TORNADO WATCH WILL LIKELY BE REQUIRED.
   
   AMA 18Z RAOB SHOWS FAIRLY STRONG LOW-LEVEL CAP...BUT DAYTIME HEATING
   IS ONGOING ALONG NRN/WRN FRINGES OF THICKER CLOUD SHIELD OF WRN N
   TX/WRN OK.  AS HEATING CONTINUES THROUGH THE AFTERNOON AND
   PERSISTENT/WEAK LOW-LEVEL CONVERGENCE CONTINUES ALONG THE
   DRYLINE...CAP SHOULD CONTINUE TO SLOWLY WEAKEN.  THIS SHOULD
   EVENTUALLY RESULT IN ISOLATED STORM DEVELOPMENT -- WITH INITIAL
   DEVELOPMENT ANTICIPATED OVER THE TX PANHANDLE WHERE SHALLOW CU FIELD
   IS NOW DEVELOPING.  FAIRLY STEEP LAPSE RATES ARE CONTRIBUTING TO
   MODERATE INSTABILITY ABOVE THE CAP LAYER...WHICH COMBINED WITH AMPLE
   SHEAR FOR UPDRAFT ROTATION SUGGESTS THAT STORMS SHOULD BECOME
   SUPERCELLULAR SHORTLY AFTER DEVELOPMENT.
   
   IN ADDITION TO THE THREAT FOR LARGE HAIL...LOCALLY-DAMAGING WINDS 
   WILL ALSO BE POSSIBLE.  DEGREE OF BOUNDARY-LAYER MOISTURE AND
   INCREASING LOW-LEVEL SHEAR BY EARLY EVENING WILL ALSO SUPPORT A
   THREAT FOR TORNADOES.
   
   ..GOSS.. 04/23/2007
   
   
   ATTN...WFO...OUN...DDC...GLD...LUB...AMA...
   
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