MESOSCALE DISCUSSION 0733
   NWS STORM PREDICTION CENTER NORMAN OK
   1134 AM CDT WED MAY 06 2009
   
   AREAS AFFECTED...NERN TX...NRN LA AND CNTRL THROUGH S CNTRL MS
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 252...253...
   
   VALID 061634Z - 061800Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   252...253...CONTINUES.
   
   THREAT FOR ISOLATED DAMAGING WIND WILL PERSIST NEXT COUPLE HOURS
   MAINLY FROM NERN LA THROUGH CNTRL AND S CNTRL MS. WW 252 AND 253 ARE
   SCHEDULED TO EXPIRE AT 18Z. REMAINING PARTS OF WW 252 WILL BE
   ALLOWED TO EXPIRE OR POSSIBLY CANCELLED EARLY. HOWEVER...DEPENDING
   ON CONVECTIVE TRENDS DURING THE NEXT HOUR...A NEW WW MIGHT BE NEEDED
   SOUTH OF WW 253...MAINLY FROM E CNTRL LA INTO S CNTRL MS.
   
   E-W ORIENTED LINE OF CONVECTION EXTENDS FROM E-CNTRL MS WWD THROUGH
   NE TX. STRONGEST PORTION OF LINE REMAINS FROM NERN LA INTO CNTRL MS
   MOVING SSEWD AT 25-30 KT. PRE-CONVECTIVE WARM SECTOR IS QUITE
   UNSTABLE WITH STEEP LAPSE RATES...AND STORMS ARE EMBEDDED WITHIN
   40-50 KT WNWLY BULK SHEAR. HOWEVER...12Z FORT WORTH RAOB AND
   FORECAST RUC SOUNDINGS INDICATE A WARM EML WITH 800 MB TEMPERATURES
   NEAR 20C HAS OVERSPREAD THE WRN PORTION OF THE WARM SECTOR. WITH WLY
   FLOW IN THE 850-700 MB LAYER...FURTHER WARMING MAY OCCUR WITH TIME.
   THE CAP IN ADDITION TO HIGHT RISES AND WEAKENING AND VEERING LOW
   LEVEL FLOW IN WAKE OF SHORTWAVE TROUGH MOVING THROUGH THE SERN
   STATES SUGGEST STORMS ALONG THE WRN END OF LINE WILL CONTINUE TO
   STRUGGLE. FARTHER EAST ACROSS MS...A WEAKER CAP AND STRONGER STORM
   RELATIVE INFLOW SUGGEST ACTIVITY MAY FORWARD PROPAGATE INTO THE
   DESTABILIZING WARM SECTOR ANOTHER FEW HOURS.
   
   ..DIAL.. 05/06/2009
   
   
   ATTN...WFO...MOB...JAN...LIX...SHV...
   
   LAT...LON   32049195 32419069 32678955 32188887 31628887 31229127
               32049195