MESOSCALE DISCUSSION 0727
   NWS STORM PREDICTION CENTER NORMAN OK
   0508 AM CDT WED MAY 06 2009
   
   AREAS AFFECTED...PORTIONS SRN OK...N-CENTRAL/NE TX...EXTREME SWRN
   AR...NWRN LA.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 249...
   
   VALID 061008Z - 061145Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 249
   CONTINUES.
   
   WW LIKELY TO BE REPLACED BY 11Z.
   
   COMPLEX OF SVR TSTMS -- INITIALLY PRODUCING LARGE HAIL OVER
   S-CENTRAL OK -- APPEARS TO BE EVOLVING INTO BOW ECHO.  GIVEN
   GEOMETRY OF AMBIENT WIND FIELDS...AND PROXIMITY TO VERY
   MOIST/BUOYANT AIR ALONG/S OF SFC WARM FRONT...THIS ACTIVITY SHOULD
   CONTINUE TO GET BETTER ORGANIZED AS WIND DAMAGE THREAT AND FORWARD
   PROPAGATIONAL MCS INTO PORTIONS EXTREME N-CENTRAL TX...THEN NERN TX
   AND NWRN LA.  SFC MESOANALYSIS SHOWS WARM FRONT NEAR RED RIVER AND
   EWD ACROSS SRN AR.  WHILE RUC FCST SOUNDINGS INDICATE SFC AIR MASS S
   OF THIS FRONT IS CAPPED...FORCED ASCENT ALONG LEADING DENSITY
   CURRENT FROM BOW COULD RESULT IN HIGH-THETAE BOUNDARY LAYER AIR
   BEING INGESTED INTO CONVECTIVE PLUME.  GIVEN STEEPNESS OF MIDLEVEL
   LAPSE RATES AND RICH LOW LEVEL MOISTURE IN PROSPECTIVE INFLOW
   REGION...MUCAPE 3000-4000 J/KG IS LIKELY TO REMAIN...AMIDST 40-50 KT
   EFFECTIVE SHEAR MAGNITUDES.  FCST FORWARD-PROPAGATIONAL MCS MOTION
   VECTORS -- WITH SOME REAR COMPONENT DUE TO BACKBUILDING -- INDICATE
   WRN FRINGES OF THIS COMPLEX MAY CLIP NERN PORTIONS DFW METRO
   AREA...WITH MAIN SWATH OF POTENTIAL DAMAGING WIND AIMING TOWARD
   TYR-GGG AND PERHAPS SHV AREAS.  SVR POTENTIAL SHOULD EXTEND NEWD TO
   INSTABILITY GRADIENT PROVIDED BY WARM FRONTAL ZONE...AND REINFORCED
   BY MCS NOW OVER SRN AR.
   
   ..EDWARDS.. 05/06/2009
   
   
   ATTN...WFO...SHV...TSA...FWD...OUN...
   
   LAT...LON   32449598 33219690 33909834 34459876 34399719 34279580
               33979491 33289400 32959346 32049335 32059556 32099584
               32449598