MESOSCALE DISCUSSION 1859
   NWS STORM PREDICTION CENTER NORMAN OK
   1036 AM CDT THU AUG 23 2007
   
   AREAS AFFECTED...ERN IA...NRN IL...SRN WI
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 231536Z - 231730Z
   
   RADAR IMAGERY SHOWS THUNDERSTORMS MOVING ENEWD AT 40 KT TOWARD SERN
   IA ARE BECOMING BETTER ORGANIZED WITH A POSSIBLE BOWING STRUCTURE
   DEVELOPING.  THIS ACTIVITY WILL BE MONITORED CLOSELY AND A WATCH MAY
   BE NEEDED ACROSS PARTS OF ERN IA/NRN IL/SRN WI IN THE 16-18Z PERIOD.
   
   
   CONVECTION IS ASSOCIATED WITH A VORTICITY MAX/SHORT WAVE TROUGH
   MOVING EWD INTO ERN NEB.  VISIBLE IMAGERY SHOWS LIMITED CLOUDS
   ACROSS ERN IA AND NRN IL WITH DIMINISHING CLOUDS POSSIBLY SPREADING
   INTO SWRN WI DURING THE NEXT FEW HOURS.  SURFACE DEW POINTS ARE
   INCREASING INTO THE LOW 70S FROM SERN IA INTO NRN IL AND EXTREME SRN
   WI...AND STRONG HEATING SHOULD CONTINUE DESTABILIZATION TREND ACROSS
   THE AREA.  WINDS ALOFT VEER FROM SSWLY NEAR THE SURFACE TO
   UNIDIRECTIONAL WSWLY ABOVE THE BOUNDARY LAYER INCREASING TO AROUND
   40 KT IN THE LOW/MID LEVELS...RESULTING IN EFFECTIVE BULK SHEAR OF
   35-45 KT DOWNSTREAM FROM THE CONVECTION.  STORMS ARE EXPECTED TO
   GRADUALLY INCREASE IN INTENSITY DURING THE LATE MORNING/EARLY
   AFTERNOON HOURS AND AREA WILL BE MONITORED FOR THE POSSIBILITY OF A
   WATCH.
   
   ..WEISS.. 08/23/2007
   
   
   ATTN...WFO...LOT...ILX...MKX...DVN...ARX...
   
   42929158 43208994 43338810 42998763 41968712 40888750
   40408815 40329007 40399108 40399184 41529146 42639179