NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...TODAY AND TONIGHT.
WEATHER HAZARDS EXPECTED:
THUNDERSTORMS...THE STRONGEST STORMS MAY PRODUCE:
WINDS IN EXCESS OF 60 MPH.
HEAVY DOWNPOURS.
FREQUENT LIGHTNING.
HAIL TO THE SIZE OF QUARTERS.
ISOLATED TORNADOES.
AREAS AFFECTED AND TIMING:
A STRONG LINE OF THUNDERSTORMS IS MOVING INTO THE SOUTHERN TIER OF
COUNTIES THIS MORNING...AND MAY BE CAPABLE OF PRODUCING SEVERE
WINDS. SHOWERS WILL OVERSPREAD THE FORECAST AREA THIS
MORNING...WITH A FEW EMBEDDED NON-SEVERE THUNDERSTORMS POSSIBLE.
SEVERE THUNDERSTORMS ARE POSSIBLE AGAIN THIS AFTERNOON AND EVENING
AHEAD OF A COLD FRONT.
DISCUSSION:
ONGOING THUNDERSTORMS THIS MORNING ARE EXPECTED TO WEAKEN AS THEY
MOVE EAST INTO MORE STABLE AIR. A WARM FRONT WILL WORK NORTH
ACROSS THE FORECAST AREA TODAY USHERING IN WARM AND MOIST AIR
BEHIND. THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND
EVENING AHEAD OF A COLD FRONT...AND SOME MAY BE SEVERE. THERE IS
SOME POTENTIAL FOR SUPERCELLS AND TORNADOES SHORTLY AFTER
THUNDERSTORMS INITIALIZE...HOWEVER THUNDERSTORMS ARE EXPECTED TO
QUICKLY CONGEAL INTO A LINE WITH DAMAGING WINDS AND LARGE HAIL
BECOMING THE PRIMARY THREATS.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANK FULL.
PERIOD OF HEAVY RAIN TODAY COULD LEAD TO RENEWED RISES ON AREA
STREAMS AND RIVERS.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.
PORTIONS OF THE UPPER ILLINOIS RIVER WILL REMAIN NEAR BANK-FULL
THROUGH SUNDAY EVENING.
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 MAY BE NECESSARY THIS AFTERNOON AND EVENING.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
