

731 

WWUS20 KWNS 132304

SEL7

SPC WW 132304

ILZ000-LMZ000-140400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 297

NWS STORM PREDICTION CENTER NORMAN OK

605 PM CDT WED MAY 13 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND NORTHEAST ILLINOIS

       LAKE MICHIGAN



EFFECTIVE THIS WEDNESDAY EVENING FROM 605 PM UNTIL 1100 PM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

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

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHEAST OF ROCKFORD

ILLINOIS TO 30 MILES SOUTH SOUTHEAST OF BLOOMINGTON ILLINOIS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 293...WW 294...WW

295...WW 296...



DISCUSSION...DISCRETE CELLS ARE FORMING IN THE ZONE OF WAA TO THE N

OF THE EARLY CONVECTION AND ONGOING MCV IN SE IL...AND WELL E OF THE

COLD FRONT BACK IN IA/MO.  LOCAL WIND PROFILES APPEAR SUPPORTIVE OF

SUPERCELLS ACROSS CENTRAL/NRN IL WHERE LOW-LEVEL SHEAR IS MAXIMIZED

AND DEEP LAYER SHEAR IS STRONGER COMPARED TO AREAS FARTHER S/SE.

GIVEN THE STRONG LOW-LEVEL SHEAR AND MOIST PROFILES...A FEW

TORNADOES MAY OCCUR DURING THE NEXT FEW HOURS.  LARGE HAIL AND

ISOLATED DAMAGING WINDS WILL ALSO BE POSSIBLE WITH THE STRONGER

STORMS...AND AS THE FRONTAL SQUALL LINE APPROACHES FROM THE W BY

EARLY TONIGHT.



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

SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE

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

500. MEAN STORM MOTION VECTOR 25035.





...THOMPSON

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