MESOSCALE DISCUSSION 0761
   NWS STORM PREDICTION CENTER NORMAN OK
   1208 PM CDT FRI MAY 08 2009
   
   AREAS AFFECTED...EXTREME IND...CNTRL AND ERN KY AND PORTIONS OF ERN
   TN
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 081708Z - 081845Z
   
   SEVERE THUNDERSTORM THREAT IS EXPECTED TO DEVELOP EWD THROUGH SRN
   IND...CNTRL AND ERN KY THROUGH CNTRL AND ERN TN THE REMAINDER OF THE
   AFTERNOON. A NEW WW WILL LIKELY BE NEEDED BEFORE 18Z.
   
   BOW-ECHO COMMA-HEAD SYSTEM REMAINS WELL ORGANIZED AND EXTENDS FROM
   SERN MO...SRN IL INTO EXTREME NERN AR. ACTIVITY IS MOVING EAST AT 50
   TO 60 KT AND WILL APPROACH THE ERN EDGE OF TORNADO WATCH 267 BY
   1830Z. PRE-CONVECTIVE WARM SECTOR IS MODERATELY UNSTABLE THROUGH W
   CNTRL TN AND WRN KY...BUT INSTABILITY DECREASES SIGNIFICANTLY WITH
   ERN EXTENT ACROSS ERN KY AND TN. A SWLY LOW LEVEL JET IS FORECAST TO
   GRADUALLY STRENGTHEN NEWD INTO THE TN VALLEY AND SRN OH VALLEY THIS
   AFTERNOON. THIS WILL CONTRIBUTE TO NEWD THETA-E ADVECTION AND
   DESTABILIZATION WITH TIME. FURTHER DESTABILIZATION WILL OCCUR AS THE
   BOUNDARY LAYER WARMS. STRENGTHENING LOW-MID LEVEL WIND FIELDS WILL
   ALSO HELP TO SUSTAIN ORGANIZED STORM STRUCTURES WITHIN THE BROADER
   MESOSCALE SYSTEM. OTHER STORMS ARE DEVELOPING ALONG WARM ADVECTION
   WING AHEAD OF THE LINE ACROSS WRN KY. THERE SOME CONCERN THAT THIS
   ACTIVITY COULD EVENTUALLY BECOME SURFACE BASED AS THE SURFACE LAYER
   WARMS. ANY DISCRETE SURFACE BASED STORMS AHEAD OF THE LINE WOULD
   LIKELY BECOME SUPERCELLULAR GIVEN FAVORABLE BULK SHEAR AND
   INCREASING HODOGRAPH SIZE WITH TIME. DAMAGING WIND...ISOLATED
   TORNADOES AND LARGE HAIL WILL BE POSSIBLE AS THE AFTERNOON
   PROGRESSES.
   
   ..DIAL.. 05/08/2009
   
   
   ATTN...WFO...MRX...JKL...ILN...LMK...OHX...HUN...
   
   LAT...LON   35458450 35278641 36288638 38328660 38508434 37618296
               35458450