MESOSCALE DISCUSSION 0788
   NWS STORM PREDICTION CENTER NORMAN OK
   1117 AM CDT SUN MAY 10 2009
   
   AREAS AFFECTED...SERN OK...EXTREME NERN TX...SRN AR...NRN LA...CNTRL
   MS AND CNTRL AL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 101617Z - 101815Z
   
   THREAT FOR HEAVY RAIN AND SOME HAIL WILL PERSIST NEXT COUPLE HOURS
   FROM SERN OK AND NERN TX THROUGH THE LOWER MS VALLEY. THREAT FOR
   HAIL AND ISOLATED DAMAGING WIND IS EXPECTED TO INCREASE DURING THE
   AFTERNOON FROM NRN LA THROUGH CNTRL MS AND AL. WW MIGHT BE NEEDED
   FOR A PORTION OF THIS AREA THIS AFTERNOON. 
   
   
   LATE THIS MORNING A QUASISTATIONARY FRONT EXTENDS FROM CNTRL AL
   WSWWD THROUGH CNTRL MS...NRN LA INTO SW TX. STORMS ARE DEVELOPING
   NORTH OF THE CONVECTIVELY ENHANCED FRONT WITHIN ZONE OF LOW LEVEL
   THETA-E ADVECTION AND LIFT SUPPORTED BY A BROAD BELT OF MODEST 15-20
   KT SWLY FLOW IN A LAYER CENTERED AROUND 850 MB. STORMS ARE EMBEDDED
   WITHIN DEEP WLY FLOW ABOVE STABLE SURFACE LAYER RESULTING IN W-E
   TRAINING OF CELLS AND RAINFALL RATES OCCASIONALLY AOA 1 INCH PER
   HOUR.
   
   STEEP MID LEVEL LAPSE RATES AND DIABATIC HEATING HAVE CONTRIBUTED TO
   MODERATE INSTABILITY OVER THE MOIST...PRE-FRONTAL WARM SECTOR FROM
   ERN TX INTO THE LOWER MS VALLEY. MORNING RAOBS AND RUC PFCS INDICATE
   A CAPPING INVERSION JUST BELOW 700 MB RESULTING FROM EWD EXTENTION
   OF EML...BUT IS PRONOUNCED WITH ERN EXTENT INTO AL. THE INVERSION
   WILL INITIALLY LIMIT OR SLOW SWD DEVELOPMENT. BUT AS THE BOUNDARY
   LAYER DESTABILIZES...POTENTIAL WILL EXIST FOR STORMS TO INTENSIFY
   ALONG LEADING OUTFLOW BOUNDARY AND SUBSEQUENTLY FORWARD PROPAGATE
   SEWD INTO DESTABILIZING WARM SECTOR OVER THE LOWER MS VALLEY REGION.
   
   
   WARM SECTOR HAS BEEN SHUNTED SOUTH OF THE STRONGER WLYS RESULTING IN
   WEAKER BULK SHEAR /25-30 KT/ SUPPORTIVE OF MAINLY MULTICELL
   CONVECTION. HOWEVER..THE THERMODYNAMIC ENVIRONMENT WILL SUPPORT A
   THREAT FOR ISOLATED STRONG WIND GUSTS AND LARGE HAIL AS STORMS
   INTENSIFY THIS AFTERNOON.
   
   ..DIAL.. 05/10/2009
   
   
   ATTN...WFO...BMX...MOB...MEG...JAN...LZK...SHV...TSA...FWD...
   OUN...
   
   LAT...LON   32528561 31708698 32319296 33559684 34599664 34199320
               33988934 33788667 32528561