MESOSCALE DISCUSSION 0507
   NWS STORM PREDICTION CENTER NORMAN OK
   0754 PM CDT SAT APR 19 2003
   
   AREAS AFFECTED...ERN OK AND XTREME SERN KS
   
   CONCERNING...TORNADO WATCH 132...
   
   VALID 200054Z - 200230Z
   
   MESOSCALE CONVECTIVE VORT CENTER APPEARS TO BE EVOLVING OVER
   ECNTRL KS WITH TAIL END OF ASSOCIATED CONVECTION GRAZING THE
   OK/KS BORDER NORTH OF BVO.  THESE TSTMS WILL MOVE NEWD INTO WS
   133 AND 134 DURING THE MID EVENING HOURS.  TO THE SOUTH...LINE OF
   TSTMS...A COUPLE OF WHICH HAVE EXHIBITED ROTATION...ARE
   BACKBUILDING INVOF MLC.  VISUAL INSPECTION FROM NORMAN AND
   SATELLITE TRENDS SUGGEST CELLS ARE INITIATING/BACKBUILDING ALONG
   THE DRY LINE ESE OF ADA AND INTERACTING WITH OUTFLOW BOUNDARIES
   FROM PREVIOUS STORMS INVOF MLC.  RESULTANT ENHANCED LOW LEVEL
   CONVERGENCE WILL CONTINUE TO SUPPORT TSTM DEVELOPMENT FROM MLC
   TOWARD THE AR BORDER THE NEXT HOUR OR SO.  LOW LEVEL STORM
   RELATIVE HELICITY VALUES WOULD STILL SUPPORT A TORNADO THREAT FOR
   A COUPLE MORE HOURS.
   
   MEANWHILE...PACIFIC COLD FRONT ACCELERATING INTO CNTRL OK WILL
   GRADUALLY OVERTAKE THE DRY LINE THAT SLOWED EARLIER FROM WEST OF
   TUL TO ADM.  ADDITIONAL TSTMS MAY DEVELOP AS THIS OCCURS ACROSS
   NERN OK...THEN BACKBUILD SWWD INTO THE ADA/ADM AREAS.  POTENTIAL
   FOR LARGE HAIL AND DAMAGING WINDS WILL EXIST WITH THIS RENEWED
   CONVECTION LATER THIS EVENING. AS A RESULT...A NEW WW WILL LIKELY
   HAVE TO BE CONFIGURED TO ENCOMPASS PARTS...IF NOT ALL...OF ERN OK
   AND PERHAPS INTO WRN AR.
   
   ..RACY.. 04/20/2003
   
   
   ATTN...WFO...LZK...SGF...SHV...TSA...ICT...OUN...
   
   33969682 35049621 36509619 37279622 37469557 37409531
   37029505 35759430 34099420