NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...THIS AFTERNOON AND TONIGHT.
WEATHER HAZARDS EXPECTED:
THUNDERSTORMS...THE STRONGEST STORMS MAY PRODUCE:
HEAVY DOWNPOURS.
FREQUENT LIGHTNING.
SMALL HAIL.
AREAS AFFECTED AND TIMING:
THERE IS A CHANCE OF THUNDERSTORMS...GENERALLY SOUTH OF A LINE
FROM ROCKFORD ILLINOIS TO RENSSELAER INDIANA LATE TONIGHT.
DISCUSSION:
AN INFLUX OF WARM HUMID AIR IS EXPECTED TO REACH NORTHERN ILLINOIS
AND NORTHWEST INDIANA TONIGHT. THIS MAY ALLOW MORE WIDESPREAD
THUNDERSTORM ACTIVITY OVER IOWA LATER TODAY AND THIS EVENING...TO
DEVELOP EASTWARD INTO THE FORECAST AREA...ESPECIALLY ACROSS
WESTERN AND SOUTHERN PORTIONS OF THE OUTLOOK AREA. THESE STORMS MAY
REACH AREAS WEST OF INTERSTATE 39 ABOUT MIDNIGHT OR SHORTLY
THEREAFTER.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANK FULL.
.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.
THUNDERSTORMS ARE LIKELY MONDAY AND MONDAY NIGHT AS A COLD FRONT
MOVES ACROSS THE FORECAST AREA. SOME STORMS MAY BECOME SEVERE
MONDAY AFTERNOON AND EVENING.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANK-FULL
THROUGH SUNDAY EVENING. PERIODS OF HEAVY RAINFALL MONDAY AND
MONDAY EVENING MAY CAUSE ADDITIONAL RISES ON AREA STREAMS AND
RIVERS.
HIGH TEMPERATURES ARE EXPECTED TO REACH WELL INTO THE 90S ON
FRIDAY...IN COMBINATION WITH DEW POINTS IN THE LOWER 70S. THIS
WILL PRODUCE HEAT INDEX VALUES BETWEEN 100 AND 105 FRIDAY
AFTERNOON.
THERE IS A CHANCE OF THUNDERSTORMS FRIDAY NIGHT AND SATURDAY.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
