Tornado Watch 297

SEL7

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