NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...TODAY AND TONIGHT.
WEATHER HAZARDS EXPECTED:
SCATTERED THUNDERSTORMS...A FEW OF THE STRONGER STORMS MAY
PRODUCE:
HEAVY DOWNPOURS.
FREQUENT LIGHTNING.
SMALL HAIL.
AREAS AFFECTED AND TIMING:
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS PORTIONS OF IOWA AND
NORTHERN MISSOURI LATE THIS AFTERNOON OR EVENING. THESE
THUNDERSTORMS ARE EXPECTED TO MOVE EAST-SOUTHEAST INTO CENTRAL
ILLINOIS AFTER MIDNIGHT TONIGHT. WHILE THE BEST CHANCES FOR
THUNDERSTORMS WILL BE SOUTH OF INTERSTATE-80...A FEW THUNDERSTORMS
MAY EXTEND INTO NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
DISCUSSION:
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A WARM FRONT
STRETCHING FROM KANSAS INTO MISSOURI THIS AFTERNOON OR EVENING. A
LOW LEVEL JET IS FORECAST TO DEVELOP THIS EVENING...SUSTAINING
THUNDERSTORMS AS THEY PROPAGATE ALONG THE FRONTAL BOUNDARY
OVERNIGHT. THE BEST CHANCE FOR THUNDERSTORMS WILL BE ACROSS
SOUTHERN PORTIONS OF THE FORECAST AREA WITH THE MAIN THREAT BEING
HEAVY RAINFALL. WITH ONLY MODEST FLASH FLOOD GUIDANCE ACROSS THE
AREA...BASINS RECEIVING HEAVY RAINFALL WILL HAVE TO BE CLOSELY
MONITORED FOR RENEWED FLOODING THREAT.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANKFULL.
PERIODS OF HEAVY RAINFALL LATE TONIGHT MAY CAUSE ADDITIONAL RISES
ON AREA STREAMS AND RIVERS.
.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.
THERE WILL BE PERIODIC CHANCES FOR THUNDERSTORMS SUNDAY THROUGH
EARLY TUESDAY.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANKFULL
THROUGH SUNDAY EVENING. PERIODS OF HEAVY RAINFALL THROUGH EARLY
TUESDAY MAY CAUSE ADDITIONAL RISES ON AREA STREAMS AND RIVERS.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
