CHICAGO — Storms sweeping across northern Illinois prompted a tornado warning, forced the cancellation of hundreds of flights at Chicago's airports and caused flooding.
The National Weather Service issued a flash flood watch for north central and northeast Illinois as thunderstorms are forecast to cross the area through Monday evening. Forecasters say the storms could dump up to two inches of rain per hour at times.
Two tornado warnings were issued for the metro-Chicago area, with one activating warning sirens downtown and prompting office buildings to send tenants into hallways away from windows.
Standing water forced the closing of the Eisenhower Expressway and part of the Chicago Transit Authority's Blue Line "L'' on the city's West Side.
The Chicago Department of Aviation is reporting delays of two hours or more at O'Hare International Airport, where more than 815 flights were cancelled. Delays of 90 minutes and the cancellation of 25 flights are reported at Midway International Airport.