MESOSCALE DISCUSSION 1247
   NWS STORM PREDICTION CENTER NORMAN OK
   0838 PM CDT THU JUN 21 2007
   
   AREAS AFFECTED...CNTRL IL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 220138Z - 220315Z
   
   POTENTIAL FOR AT LEAST ISOLATED DAMAGING WINDS AND HAIL IS EXPECTED
   TO DEVELOP E OF WW 439 BY 02Z.  AN ADDITIONAL WW MAY BE NECESSARY.
   
   REGIONAL RADAR IMAGERY INDICATES THAT SRN PORTION OF LONG-LIVED MCS
   HAS DEVELOPED A BOW CONFIGURATION OVER THE PAST HOUR WITH SLIGHT
   INCREASE IN SYSTEM SPEED NOTED TO NEAR 35KT.  RECENT SURFACE
   OBSERVATIONS FROM MUSCATINE AND BURLINGTON IA INDICATE WIND GUSTS OF
   40-45KT WITH PASSAGE OF GUST FRONT.  DOWNSTREAM AIR MASS ACROSS
   CNTRL IL WAS WELL SAMPLED BY 22/00Z ILX SOUNDING WHERE STEEP
   LOW-LEVEL LAPSE RATES AND A RELATIVELY MOIST BOUNDARY LAYER WERE
   CONTRIBUTING TO MLCAPES OF 2000-2500 J/KG.  THE ACCOMPANYING
   VERTICAL WIND PROFILE SHOWED LIGHT SW/W WINDS VEERING TO NWLY IN THE
   MID AND UPPER TROPOSPHERE...SUPPORTIVE OF DOWNSTREAM COLD POOL
   ELONGATION.
   
   THEREFORE...EXPECT MCS TO CONTINUE ESEWD FOR AT LEAST THE NEXT FEW
   HOURS...WITH ADDITIONAL STORM DEVELOPMENT OCCURRING ALONG
   QUASI-STATIONARY BOUNDARY EXTENDING FROM INTERSECTION WITH MCS SW OF
   MLI TO JUST S OF BMI TO NEAR CMI.  LARGE HAIL AND LOCALLY DAMAGING
   WINDS WILL REMAIN THE PRIMARY SEVERE WEATHER THREATS.
   
   ..MEAD.. 06/22/2007
   
   
   ATTN...WFO...LOT...ILX...DVN...
   
   41039038 41298996 41368960 41118898 40578874 40278875
   39758912 39749008 40079061 40429060