MESOSCALE DISCUSSION 0685
   NWS STORM PREDICTION CENTER NORMAN OK
   0253 PM CDT FRI MAY 04 2007
   
   AREAS AFFECTED...WRN KS...PARTS OF WRN OK/ERN TX PNHDL
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 041953Z - 042200Z
   
   TRENDS ARE BEING CLOSELY MONITORED FOR SIGNS OF CONVECTIVE
   INITIATION.  ALTHOUGH TIMING IS STILL A BIT UNCERTAIN...ONE OR MORE
   TORNADO WATCHES WILL PROBABLY BE REQUIRED LATE THIS AFTERNOON.
   
   MOISTENING SOUTHERLY LOW-LEVEL FLOW AND STRONG DAYTIME HEATING ALONG
   SOUTHERN HIGH PLAINS DRY LINE...INTO THE VICINITY OF WEAK SURFACE
   LOW OVER SOUTHWEST KANSAS...IS CONTRIBUTING TO STRONG
   DESTABILIZATION.  RUC GUIDANCE INDICATES MIXED LAYER CAPE IS
   INCREASING INTO THE 3000-4000 J/KG RANGE...THOUGH MID-LEVEL
   SUBSIDENCE/SHORT WAVE RIDGING ALOFT IS CURRENTLY INHIBITING
   CONVECTIVE DEVELOPMENT.
   
   HOWEVER...MID/UPPER FORCING ASSOCIATED WITH AN IMPULSE LIFTING OUT
   OF AMPLIFIED WESTERN TROUGH IS BEGINNING TO SHIFT EAST OF THE
   CENTRAL/SOUTHERN ROCKIES.  AND...LATEST RUC GUIDANCE SUGGESTS WEAK
   LOWER/MID TROPOSPHERIC COOLING HAS OCCURRED ACROSS WESTERN KANSAS
   INTO THE TEXAS PANHANDLE ASSOCIATED WITH IMPULSE ALREADY LIFTING
   NORTHWARD THROUGH THE NORTH CENTRAL HIGH PLAINS.  ALTHOUGH
   UNCERTAINTY DOES EXISTS CONCERNING TIMING OF CONVECTIVE
   INITIATION...MUCH OF MODEL GUIDANCE SUGGESTS THAT THIS COULD OCCUR
   AS EARLY AS 22-23Z.  THIS SEEMS MOST PROBABLE WHERE FORCING WILL BE
   STRONGEST NEAR SURFACE LOW...BUT INITIATION OF WIDELY SCATTERED
   STORMS MAY QUICKLY FOLLOW SUITE.
   
   STORM DEVELOPMENT/INTENSIFICATION WILL LIKELY BE VERY RAPID ONCE CAP
   BREAKS.  AND...LARGE CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS BENEATH
   40-50 KT CYCLONIC WEST SOUTHWESTERLY 500 MB FLOW WILL BE FAVORABLE
   FOR TORNADOES...IN ADDITION TO THE RISK OF VERY LARGE HAIL. 
   ISOLATED STRONG TORNADOES ARE POSSIBLE...PARTICULARLY AS LOW-LEVEL
   JET STRENGTHENS NEAR/SHORTLY AFTER 04/00-01Z.
   
   ..KERR.. 05/04/2007
   
   
   ATTN...WFO...ICT...OUN...GID...DDC...GLD...LUB...AMA...
   
   38660150 39630029 39799943 38919814 37039815 35499848
   34599966 34380083 35150103 35890059 36590025 36920043
   37260135