MESOSCALE DISCUSSION 1349
   NWS STORM PREDICTION CENTER NORMAN OK
   0720 PM CDT TUE JUN 21 2011
   
   AREAS AFFECTED...PARTS OF SRN IL
   
   CONCERNING...TORNADO WATCH 531...532...
   
   VALID 220020Z - 220145Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 531...532...CONTINUES.
   
   IT IS POSSIBLE THAT THE WATCH COULD BE EXTENDED LOCALLY IN TIME FOR
   AN HOUR OR TWO...BUT A NEW WW IS NOT CURRENTLY PLANNED.
   
   AHEAD OF AN INITIAL WEAKENING SURFACE COLD FRONT...LOW-LEVEL WARM
   ADVECTION AND LIFT OF MODERATELY UNSTABLE AIR /CAPE ON THE ORDER OF
   2000 J PER KG/ HAS SUPPORTED REGENERATION OF STRONG/SEVERE STORM
   DEVELOPMENT ALONG THE STALLED WESTERN FLANK OF OUTFLOW ASSOCIATED
   WITH A WEAKENING DOWNSTREAM MESOSCALE CONVECTIVE SYSTEM.  IN THE
   PRESENCE OF FAVORABLE SHEAR BENEATH 40+ KT WESTERLY 500 MB FLOW...
   THIS ACTIVITY COULD POSE AT LEAST A LINGERING SEVERE HAIL THREAT
   INTO THE 01-03Z TIME FRAME ACROSS SOUTHERN ILLINOIS...PARTICULARLY
   NEAR THE INTERSTATE 64 CORRIDOR.
   
   ..KERR.. 06/22/2011
   
   
   ATTN...WFO...PAH...ILX...LSX...
   
   LAT...LON   38469006 38948966 39088879 38788827 38368805 37928834
               37798904 37848955 37929003 37939027 38469006