NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...THIS AFTERNOON AND TONIGHT.
WEATHER HAZARDS EXPECTED:
THUNDERSTORMS...SOME MAY PRODUCE:
WIND GUSTS UP TO 60 MPH.
HEAVY RAINFALL.
FREQUENT LIGHTNING.
AREAS AFFECTED AND TIMING:
ISOLATED TO SCATTERED THUNDERSTORMS MAY CONTINUE TO
DEVELOP ON AND OFF ACROSS NORTHERN ILLINOIS THROUGH THE
AFTERNOON...MAINLY ALONG AND NORTH OF INTERSTATE 88 AND
INTERSTATE 290. MORE WIDESPREAD THUNDERSTORM DEVELOPMENT MAY
BEGIN AS EARLY AS LATE THIS AFTERNOON ACROSS NORTH CENTRAL
ILLINOIS AND SPREAD EASTWARD INTO NORTHEAST ILLINOIS EARLY THIS
EVENING...PRIMARILY ALONG AND NORTH OF INTERSTATE 88 AND
INTERSTATE 290. AREAS SOUTH OF THESE HIGHWAYS HAVE A CHANCE FOR
THUNDERSTORMS AS WELL. THUNDERSTORMS ARE EXPECTED TO CONTINUE
THROUGH THE NIGHT ALONG AND NORTH OF INTERSTATE 80.
DISCUSSION:
A STALLED OR SLOW MOVING FRONTAL BOUNDARY ACROSS NORTHERN
ILLINOIS WILL BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT LATE
THIS AFTERNOON THROUGH TONIGHT. PLACEMENT OF THE FRONT WILL BE
KEY IN IDENTIFYING THE AREA WHERE THE HEAVIEST RAIN WILL FALL.
AT THIS TIME...THE GREATEST POTENTIAL FOR HEAVY RAIN AND FLASH
FLOODING WILL BE ALONG AND NORTH OF INTERSTATE 80 INTO FRIDAY
MORNING. IN ADDITION RENEWED CONCERNS FOR STREAMS AT OR NEAR
BANKFULL MAY BECOME FURTHER SWOLLEN IF THUNDERSTORMS ARE SLOW
MOVING.
HIGH HEAT AND HUMIDITY WILL BE A CONCERN ACROSS AREAS FROM
PONTIAC TO KANKAKEE TO RENSSELAER WITH HEAT INDEX VALUES BETWEEN
100 AND 110 DEGREES POSSIBLE THIS AFTERNOON.
.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.
THERE IS A CHANCE FOR THUNDERSTORMS THURSDAY THROUGH FRIDAY.
THUNDERSTORMS MAY PRODUCE VERY HEAVY RAINFALL... ESPECIALLY FOR
LOCATIONS NORTH OF THE INTERSTATE 80 CORRIDOR.
HEAT AND HUMIDITY RETURNS TO NORTHERN ILLINOIS AND NORTHWEST
INDIANA THURSDAY...MAINLY SOUTH OF INTERSTATE 80 WHERE HEAT
INDICES WILL RANGE FROM 100 TO 110 DEGREES.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED FROM LATE THIS AFTERNOON THROUGH TONIGHT.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
