Chicago experienced one of its heaviest rainfall events since September 2023 on Tuesday night, leading to water rescues and flooded basements.An outflow boundary surging northward into the city from earlier storms south of Interstate 80 led to one lone thunderstorm cell developing over Chicago just before 9 p.

The National Weather Service issued a flash flood warning at 9:46 p.m. Tuesday night for Chicago and Cicero and the situation quickly escalated.

Heavy rainfall fell on Chicago’s West Side during a short amount of time Tuesday night, leaving some drivers flooded out in underpasses and several homeowners in ankle-deep water in their basements. A Flash Flood Warning was in effect for several hours before the water receded by early Wednesday morning.