

000 

WWUS20 KWNS 010137

SEL3

SPC WW 010137

ILZ000-INZ000-LMZ000-010500-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 103

NWS STORM PREDICTION CENTER NORMAN OK

835 PM CDT SAT MAR 31 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHEAST AND EAST CENTRAL ILLINOIS

       NORTHWEST AND WEST CENTRAL INDIANA

       LAKE MICHIGAN



EFFECTIVE THIS SATURDAY NIGHT FROM 835 PM UNTIL MIDNIGHT CDT.



TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS

TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE

MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH NORTHWEST OF

MEIGS FIELD ILLINOIS TO 5 MILES SOUTHWEST OF DANVILLE ILLINOIS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU3).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS.



OTHER WATCH INFORMATION...CONTINUE...WW 101...WW 102...



DISCUSSION...CNTRL IL QLCS EXPECTED TO CONTINUE NEWD TOWARD THE CHI

AREA AS CELLS MOVE MORE RAPIDLY NNE ALONG IT.

STRENGTHENING...LARGELY UNIDIRECTIONAL DEEP WIND FIELD ASSOCIATED

WITH EJECTING SHORTWAVE TROUGH OVER IA WILL MAINTAIN SHEAR PROFILES

TO SUPPORT EMBEDDED SUPERCELLS WITH POSSIBLE HIGH WIND/ISOLATED

SPIN-UP TORNADOES DESPITE DIMINISHING SFC-BASED INSTABILITY WITH EWD

EXTENT/TIME.  TORNADO THREAT APPEARS GREATEST WHERE SQLN INTERSECTS

WITH WNW/ESE-ORIENTED STATIONARY/WARM FRONT IN NRN IL.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND

GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.

MEAN STORM MOTION VECTOR 21040.





...CORFIDI

