Full Notification

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

WEATHER HAZARDS EXPECTED:

THUNDERSTORMS...SOME OF WHICH MAY BE SEVERE WITH:
HAIL TO THE SIZE OF GOLF BALLS.
DAMAGING WINDS.
ISOLATED FLASH FLOODING.
AN OUTSIDE CHANCE OF A TORNADO.

AREAS AFFECTED AND TIMING:

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE THIS
AFTERNOON ACROSS FAR NORTHERN ILLINOIS AND EXPAND IN COVERAGE
THIS EVENING ACROSS MUCH OF NORTH CENTRAL AND NORTHEAST
ILLINOIS...AND INTO NORTHWEST INDIANA. STORMS WILL SLOWLY
DIMINISH IN COVERAGE AND INTENSITY OVERNIGHT. THE SEVERE
WEATHER THREAT LOOKS TO BE AT ITS PEAK ALONG AND NORTH OF
INTERSTATE 80...AND MAINLY BETWEEN 6 PM AND 1 AM.

DISCUSSION:

A WEAK COLD FRONT STRETCHED FROM CENTRAL WISCONSIN SOUTHWEST
ACROSS IOWA LATE THIS MORNING. THIS FRONT WILL MOVE SLOWLY
SOUTHEAST INTO THE AREA THIS EVENING...INTO WARM AND UNSTABLE AIR
IN PLACE ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA. SCATTERED
THUNDERSTORMS WILL LIKELY DEVELOP ALONG OR JUST AHEAD OF THE FRONT
ACROSS FAR NORTHERN ILLINOIS LATE THIS AFTERNOON. THESE INITIAL
STORMS WILL BE CAPABLE OF LARGE HAIL AND STRONG WINDS...ALONG
WITH AN OUTSIDE CHANCE OF A TORNADO. AS WINDS ALOFT INCREASE THIS
EVENING STORMS WILL LIKELY ORGANIZE AND HAVE THE GREATEST
POTENTIAL OF PRODUCING STRONG WINDS AS THEY EVOLVE SOUTHEAST
ACROSS THE REGION...INCLUDING ACROSS THE CHICAGO METRO AREA. THE
STORMS WILL MAINTAIN A HAIL THREAT AS WELL AS AN ISOLATED FLASH
FLOOD THREAT...AS IT IS POSSIBLE FOR A SEVERAL HOUR PERIOD OF
STORMS IN SOME COMMUNITIES. STORMS SHOULD SLOWLY DIMINISH IN
INTENSITY OVERNIGHT...WITH A SLOW PROGRESSION SOUTHWARD.