MESOSCALE DISCUSSION 1009
   NWS STORM PREDICTION CENTER NORMAN OK
   0304 PM CDT TUE JUN 09 2009
   
   AREAS AFFECTED...SERN MO / FAR SRN IL / FAR WRN KY
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 092004Z - 092130Z
   
   THE THREAT FOR SEVERE STORMS WILL LIKELY DEVELOP E OF TORNADO WATCH
   357 WITHIN THE NEXT 1-2 HOURS AND AN ADDITIONAL WW MAY BE REQUIRED.
   
   AS OF 1950Z...UPSTREAM RADAR DATA INDICATED MORE DISCRETE STORMS
   EXHIBITING SUPERCELL CHARACTERISTICS OVER SHANNON...DENT AND PULASKI
   COUNTIES IN MO...AND A MORE ORGANIZED TSTM COMPLEX JUST S OF SZL. 
   THIS ACTIVITY IS OCCURRING TO THE N OF A QUASI-STATIONARY BOUNDARY
   EXTENDING FROM N OF SGF TO NEAR CGI TO NEAR EVV AS OF 20Z.  AIR MASS
   INVOF THIS BOUNDARY REMAINS MOIST AND MODERATELY UNSTABLE WITH
   MLCAPE OF 1500-2000 J/KG.  MOREOVER...THE PRESENCE OF 45-60 KT
   MIDLEVEL FLOW IS RESULTING IN SUFFICIENT DEEP LAYER SHEAR TO SUPPORT
   ORGANIZED STORM STRUCTURES INCLUDING SUPERCELLS AND BOWS.
   
   THE PRIMARY UNCERTAINTY IS THE EXTENT OF THE SEVERE THREAT.  CURRENT
   PLAN VIEW VWP AND PROFILER DATA INDICATE 20 KT SLY WINDS ABOVE THE
   SURFACE OVER SWRN MO WITH LIGHT SWLY WINDS ABOVE THE GROUND FROM
   SERN MO INTO WRN KY.  THUS...REGION RESIDES WITHIN A ZONE OF WEAK
   MASS DIVERGENCE THROUGH A DEEPER LAYER.  CURRENT THINKING IS THAT AT
   LEAST ISOLATED STORMS WILL DEVELOP E OF WW 357 WITHIN THE NEXT 1-2
   HOURS...BUT THE POTENTIAL FOR NEW STORM DEVELOPMENT ALONG THE
   BOUNDARY REMAINS IN QUESTION BASED ON THE ABOVE-MENTIONED
   OBSERVATIONS.  SEVERE HAIL AND LOCALLY DAMAGING WIND GUSTS WOULD BE
   THE PRIMARY THREATS WITH ANY STORMS MOVING INTO THE AREA THROUGH
   THIS AFTERNOON.
   
   ..MEAD.. 06/09/2009
   
   
   ATTN...WFO...PAH...MEG...LSX...SGF...
   
   LAT...LON   37119106 37689098 37919032 37868954 37478865 36928864
               36538933 36529057 36639087 37119106