MESOSCALE DISCUSSION 0645
   NWS STORM PREDICTION CENTER NORMAN OK
   0155 PM CDT THU APR 30 2009
   
   AREAS AFFECTED...NERN OK...NWRN AR
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 301855Z - 302100Z
   
   REMNANT MCV IS SHIFTING ENEWD ACROSS NCNTRL AR WITH BREAKS IN
   EXPANSIVE CLOUDINESS NOW OCCURRING NORTH OF OUTFLOW BOUNDARY WITHIN
   COOLER AIRMASS OVER WCNTRL AR/ECNTRL OK.  WEAK WARM ADVECTION
   APPEARS PRIMARILY RESPONSIBLE FOR ONGOING ELEVATED CONVECTION ALONG
   WRN PERIPHERY OF SFC MESO-SCALE COLD DOME.  WITH TIME THIS ACTIVITY
   MAY CONGEAL AND BECOME ROOTED A BIT LOWER AS IT APPROACHES STEEPER
   BOUNDARY LAYER LAPSE RATE ENVIRONMENT ALONG I-40 OVER AR.  IF THIS
   OCCURS...UPWARD GROWTH IS POSSIBLE AND SEVERE THREAT WOULD INCREASE.
    LARGE HAIL AND DAMAGING WINDS ARE THE MAIN SEVERE THREATS.
   
   ..DARROW.. 04/30/2009
   
   
   ATTN...WFO...LZK...SGF...TSA...
   
   LAT...LON   36939550 36219399 35699265 34669292 35119558 36419670
               36939550