MESOSCALE DISCUSSION 0663
   NWS STORM PREDICTION CENTER NORMAN OK
   0936 PM CDT FRI MAY 01 2009
   
   AREAS AFFECTED...NRN AR
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 223...
   
   VALID 020236Z - 020400Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 223
   CONTINUES.
   
   THE SEVERE THREAT ACROSS NRN AR WILL LIKELY CONTINUE BEYOND WATCH
   EXPIRATION AND MAY EXPAND SWWD WITH TIME ACROSS SERN OK LATE THIS
   EVENING. LARGE HAIL AND WIND DAMAGE SHOULD BE THE PRIMARY THREATS
   ALTHOUGH A TORNADO CAN NOT BE RULED. WW ISSUANCE WILL LIKELY BE
   NEEDED TO REPLACE WW 223 OVER NRN AR AND SERN OK.
   
   LATEST SFC ANALYSIS SHOWS A SLOW MOVING FRONTAL BOUNDARY ACROSS NRN
   AR EXTENDING SWWD INTO ERN OK. THE STORMS IN NWRN AR ARE LOCATED
   JUST NORTH OF THE BOUNDARY ON THE WRN EDGE OF A LOW-LEVEL JET. THE
   LOW-LEVEL FLOW ALONG WITH MODERATE INSTABILITY SHOULD HELP SUSTAIN
   THE STORMS EWD ACROSS NCNTRL AR LATE THIS EVENING. FURTHER SOUTHWEST
   ACROSS SERN OK...NEW CELLS APPEAR LIKELY TO INITIATE LATE THIS
   EVENING WHICH IS SUPPORTED BY SHORT-TERM MODEL FORECASTS. THE
   ENVIRONMENT IN SERN OK IS CHARACTERIZED BY MODERATE INSTABILITY AND
   ABOUT 40 KT OF VERTICAL SHEAR EVIDENT ON THE PROFILER NEAR THE OK/AR
   STATE-LINE. THIS SHOULD BE SUFFICIENT FOR AN ISOLATED SEVERE THREAT
   WITH HAIL AND WIND DAMAGE POSSIBLE. A NEW WW WILL LIKELY BE NEEDED
   ALONG THE BOUNDARY IN NRN AR AND SE OK BEFORE THE TOP OF THE HOUR.
   
   ..BROYLES.. 05/02/2009
   
   
   ATTN...WFO...PAH...MEG...LZK...SGF...SHV...TSA...FWD...OUN...
   
   LAT...LON   35849605 36649480 36699252 36669106 36199077 35219065
               34709087 34699258 34059439 33589540 33539623 33799718
               34229748 34859754 35079718 35849605