MESOSCALE DISCUSSION 2120
   NWS STORM PREDICTION CENTER NORMAN OK
   0957 PM CDT THU OCT 18 2007
   
   AREAS AFFECTED...LOWER MI/MUCH OF INDIANA INTO NORTHERN OH
   
   CONCERNING...TORNADO WATCH 724...
   
   VALID 190257Z - 190430Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 724 CONTINUES.
   
   TORNADO WATCH 724 CONTINUES UNTIL 04Z...WITH A RISK OF ISOLATED
   TORNADOES...DAMAGING WIND GUSTS...AND SOME HAIL. AN ADDITIONAL
   REPLACEMENT TORNADO WATCH WILL BE REQUIRED BY THE 0330Z-0400Z
   TIMEFRAME...WITH AN EASTWARD EXPANSION ACROSS THE REMAINDER OF
   SOUTHEAST LOWER MI /INCLUDING THE DETROIT METRO/ AND PORTIONS OF
   NORTHERN OH /INCLUDING THE TOLEDO AND FINDLAY AREAS/.
   
   QUASI-DISCRETE SUPERCELLS CONTINUE ACROSS A LARGE PART OF TORNADO
   WATCH 724...MOST PROLIFIC FROM NORTHEAST INDIANA INTO CENTRAL LOWER
   MI. WHILE TOTAL INSTABILITY/SURFACE DEWPOINTS ARE MARGINAL
   ESPECIALLY WITH NORTH EXTENT...TURBULENT MIXING/AMPLE LOW LEVEL CAPE
   COUPLED WITH DRAMATICALLY STRONG LOW LEVEL HODOGRAPH
   CURVATURE/ENLARGED SRH WILL CONTINUE TO MAINTAIN A DISTINCT LOW
   LEVEL MESOCYCLONE/TORNADO RISK INTO THE OVERNIGHT FROM THE FAR
   NORTHEAST INDIANA INTO EAST CENTRAL/SOUTHEAST LOWER MI AND PORTIONS
   OF NORTHERN OH. WITHIN THIS CORRIDOR...LOCAL WSR-88D VWP DATA IS
   SUGGESTIVE OF 0-1 KM SRH OF 400-700 M2/S2.
   
   ..GUYER.. 10/19/2007
   
   
   ATTN...WFO...CLE...ILN...DTX...APX...IWX...GRR...IND...
   
   44538400 44018252 41998237 40788261 40008543 39028663
   39768738 43488516