Severe Weather Potential Tonight. See Below

SEVERE THUNDERSTORMS ARE POSSIBLE FROM LATE THIS AFTERNOON THROUGH
THE NIGHT TONIGHT.

WEATHER HAZARDS EXPECTED:

STRONG TO SEVERE THUNDERSTORMS CAPABLE OF PRODUCING:

* LARGE HAIL UP TO 1 TO 2 INCHES IN DIAMETER.

* STRONG DAMAGING WIND GUSTS OF 60 TO 70 MPH.

* ISOLATED TORNADOES POSSIBLE.

* LOCALLY HEAVY RAINFALL.

AREAS AFFECTED AND TIMING:

STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP BY THE LATE
AFTERNOON OVER NORTHWESTERN ILLINOIS. SEVERE THUNDERSTORM
POTENTIAL WILL SPREAD EAST AND SOUTH ACROSS THE ENTIRE OUTLOOK
AREA THROUGH THE EVENING AND OVERNIGHT TONIGHT.

DISCUSSION:

INCREASING SOUTHERLY FLOW AHEAD OF A DEVELOPING LOW PRESSURE
SYSTEM AND AN ASSOCIATED STRONG COLD FRONT WILL BRING INCREASING
TEMPERATURES AND LOW LEVEL MOISTURE TO THE REGION TODAY. A CAPPING
INVERSION SHOULD BE IN PLACE UNTIL LATE THIS AFTERNOON INHIBITING
THUNDERSTORM DEVELOPMENT.

BY EARLY THIS EVENING...THE INVERSION SHOULD BREAK AND
THUNDERSTORMS SHOULD RAPIDLY DEVELOP OVER NORTHWESTERN ILLINOIS.
INITIALLY...THERE WILL BE POTENTIAL FOR DISCRETE SUPERCELLS OVER
PORTIONS OF THE OUTLOOK AREA WEST AND SOUTH OF A LINE FROM
ROCKFORD TO HERSCHER. LARGE HAIL...DAMAGING WINDS AND ISOLATED
TORNADOES WILL BE POSSIBLE WITH THESE STORMS.

BY LATE EVENING...CONVECTIVE MODE WILL TRANSITION TO A LINE OF
STRONG TO SEVERE STORMS...ALIGNING ALONG AND AHEAD OF THE COLD
FRONT. THESE STORMS WILL BE CAPABLE OF PRODUCING DAMAGING STRAIGHT
LINE WINDS...LARGE HAIL AND LOCALLY HEAVY RAINFALL. THE
PROGRESSION OF THE SOUTHERN PORTION OF THE FRONT MAY SLOW
DOWN...ALLOWING FOR WIDESPREAD HEAVY RAINFALL...ESPECIALLY SOUTH
OF INTERSTATE 80. THIS AREA MAY SEE WIDESPREAD RAINFALL OF 1 TO 2
INCHES WILL LOCALLY HIGHER AMOUNTS POSSIBLE.