MESOSCALE DISCUSSION 0769
   NWS STORM PREDICTION CENTER NORMAN OK
   0835 PM CDT FRI MAY 08 2009
   
   AREAS AFFECTED...NRN IL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 275...
   
   VALID 090135Z - 090300Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 275
   CONTINUES.
   
   A WELL DEFINED BOW WITH EMBEDDED SUPERCELLS CONTINUES TO MOVE
   RAPIDLY ESEWD INTO NWRN IL AT 40-50 MPH. THE 00Z DVN AND ILX
   SOUNDINGS BOTH INDICATE STRONG DEEP LAYER WIND FIELDS ARE IN PLACE.
   MID LEVEL TEMPERATURES ARE MUCH COOLER AT DVN THAN AT ILX.
   THUS...DESPITE DEWPOINTS INTO THE UPPER 50S F AHEAD OF THESE
   CELLS...OVERALL INSTABILITY LEVELS WILL BE LIMITED WITH SWD EXTENT
   AND THIS MAY HELP TO MAINTAIN A DISTINCT SRN EDGE TO THIS SEVERE
   CONVECTION.
   
   LINEAR EXTRAPOLATION PUTS THE SRN MOST CELL AT THE SERN CORNER OF WW
   275 AT AROUND 0230Z...OR JUST N OF PIA. THUS...A NEW WW MAY BE
   NEEDED SOON ACROSS NRN IL.
   
   WHILE ACTIVITY FARTHER N HAS NOT BEEN AS STRONG...DEWPOINTS CONTINUE
   TO RISE AND TEMPERATURES ARE COOLER ALOFT. A FEW STRONG TO SEVERE
   STORMS WITH STRONG WINDS AND HAIL CANNOT BE RULED OUT IN THE CHICAGO
   AREA BETWEEN 03-06Z.
   
   ..JEWELL.. 05/09/2009
   
   
   ATTN...WFO...LOT...ILX...MKX...DVN...
   
   LAT...LON   40238780 40028870 40178933 40319054 40649120 41029121
               41589051 42219008 42558920 42568822 42258783 41538765
               40758767 40238780