Updated 9/3/11 5:20 p.m.

CHICAGO (STMW) – After three straight days of hot and humid weather, cooler air is expected to move into the Chicago area for the remainder of the holiday weekend — but not before some potentially strong Saturday night thunderstorms.

A severe thunderstorm watch is in effect until 11 p.m. Saturday for Cook, DuPage, Kane, Kankakee and Will counties, according to the National Weather Service’s website.

Showers and thunderstorms are likely between 7 p.m. and 1 a.m. Sunday, the weather service said. The storms could have wind gusts of more than 60 miles per hours, two-inch hail and isolated heavy downpours.

Runoff from this excessive rainfall, which could produce up to two inches of rain in areas, could cause minor flooding — especially along small streams and near low water crossings.

A flood advisory is also in effect until 9 p.m. for small streams in southeaster Cook County, southeaster DuPage County, northwestern Lake County and central Will County, the weather service said.

The thunderstorms will also bring cooler air, the weather service said. The high temperature Sunday is only expected to be 73 degrees, and it is only expected to get to 67 degrees on Labor Day.

© Sun-Times Media Wire Chicago Sun-Times 2011. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.

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