Outlook

.DAY ONE...TONIGHT.

WEATHER HAZARDS EXPECTED:

CHANCE OF THUNDERSTORMS...SOME WHICH MAY PRODUCE:
LOCALLY HEAVY RAINFALL.
CLOUD TO GROUND LIGHTNING.
HAIL TO THE SIZE OF QUARTERS.
WIND GUSTS OVER 60 MPH.

AREAS AFFECTED AND TIMING:

THERE IS A CHANCE OF THUNDERSTORMS TONIGHT...ESPECIALLY AFTER
MIDNIGHT. THE GREATEST THREAT OF THUNDERSTORMS APPEARS TO BE
NORTH OF INTERSTATE 88.

DISCUSSION:

THUNDERSTORMS WILL LIKELY DEVELOP LATE THIS AFTERNOON OR EARLY
THIS EVENING OVER IOWA. THESE STORMS ARE EXPECTED TO TRACK
EASTWARD...GENERALLY ALONG AND NORTH OF AN ADVANCING WARM FRONT
WHICH IS EXPECTED TO REACH THE WISCONSIN BORDER BY EARLY SUNDAY
MORNING. IT CURRENTLY APPEARS AS THOUGH THE GREATEST CHANCE OF
THUNDERSTORMS IS OVER SOUTHERN WISCONSIN...HOWEVER SOME STORMS
COULD CLIP FAR NORTHERN ILLINOIS. IF ANY STORMS OF THE STORMS
TONIGHT DO MAKE IT INTO NORTHERN ILLINOIS THEY WILL HAVE THE
POTENTIAL TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

A SIGNIFICANT AND POTENTIALLY DANGEROUS OUTBREAK OF SEVERE
THUNDERSTORMS APPEARS LIKELY LATE SUNDAY AFTERNOON OR MORE
LIKELY SUNDAY EVENING. TORNADOES...DAMAGING WINDS...AND LARGE
HAIL ALL APPEAR QUITE POSSIBLE.

AN INTENSE SPRING STORM SYSTEM WILL TRACK FROM THE CENTRAL
PLAINS TODAY NORTHEAST INTO THE UPPER GREAT LAKES SUNDAY.
STRONG SOUTHERLY WINDS WILL USHER UNSEASONABLY WARM AND MOIST
AIR NORTHWARD INTO THE REGION SUNDAY...RESULTING IN THE
ATMOSPHERE BECOMING VERY UNSTABLE DURING THE AFTERNOON AND
EVENING. THE COMBINATION OF INSTABILITY AND VERY STRONG WINDS
ALOFT WILL CREATE AN ENVIRONMENT FAVORABLE FOR SEVERE
THUNDERSTORMS CAPABLE OF PRODUCING STRONG AND POTENTIALLY LONG
TRACKED TORNADOES...AS WELL AS WIDESPREAD SIGNIFICANT DAMAGING
WINDS. IT IS DIFFICULT TO FORECAST IN ADVANCE WHETHER STORMS
WILL REMAIN MORE ISOLATED OR CONGEAL INTO A LINE...WHICH HAS
MAJOR IMPLICATIONS OF WHETHER THE GREATER SEVERE THREAT WILL BE
DAMAGING WINDS OR TORNADOES.

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY INTO THURSDAY
NIGHT.

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