NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...TONIGHT.
WEATHER HAZARDS EXPECTED:
THUNDERSTORMS...SOME COULD PRODUCE:
DAMAGING WINDS IN EXCESS OF 60 MPH.
HAIL TO THE SIZE OF HALF DOLLARS.
FREQUENT CLOUD TO GROUND LIGHTNING.
MODERATE TO HEAVY RAIN.
AREAS AFFECTED AND TIMING:
A COLD FRONT CURRENTLY MOVING ACROSS NORTHWESTERN AND NORTH
CENTRAL ILLINOIS WILL MOVE SOUTHEAST ACROSS NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA LATE THIS AFTERNOON INTO
EARLY THIS EVENING. THUNDERSTORMS ARE EXPECTED TO RAPIDLY
DEVELOP ALONG THE FRONT BETWEEN 4 AND 6 PM THIS AFTERNOON.
THESE THUNDERSTORMS ARE EXPECTED TO AFFECT AREAS MAINLY ALONG
AND SOUTHEAST OF A LINE FROM NEAR CHICAGO SOUTHWESTWARD TO
NEAR OTTAWA ILLINOIS.
DISCUSSION:
STRONG INSTABILITY IS IN PLACE AHEAD OF THE COLD FRONT.
HOWEVER...A CAPPING INVERSION IS KEEPING THUNDERSTORMS FROM
FORMING AT THE PRESENT. HOWEVER...A POTENT UPPER LEVEL
DISTURBANCE NOW APPROACHING THE AREA SHOULD INTERACT WITH THE
LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONTAL ZONE TO WEAKEN
AND BREAK THROUGH THE CAP. THIS IS EXPECTED TO RESULT IN
EXPLOSIVE THUNDERSTORM DEVELOPMENT. THE ATMOSPHERE IN WHICH
THESE STORMS DEVELOP WILL SUPPORT STRONG TO SEVERE
THUNDERSTORMS WITH STRONG WINDS AND LARGE HAIL. THE
THUNDERSTORMS SHOULD QUICKLY COME TO AN END EARLY THIS EVENING
AS THE FRONT CLEARS THE AREA.
.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.
THERE IS A CHANCE OF THUNDERSTORMS SUNDAY NIGHT THROUGH MONDAY.
.SPOTTER INFORMATION STATEMENT...
SPOTTERS MAY BE NEEDED LATE THIS AFTERNOON THROUGH EARLY THIS EVENING.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
