Chicago was under a flood watch Thursday night in anticipation of thunderstorms expected to move through the city, according to the National Weather Service.
The flood watch, expected to expire Friday at 7 a.m., was in effect for all of Cook County, as well as areas of surrounding DuPage, Kane, Kendall, Lake, McHenry and Will counties and cautioned of flash flooding due to excessive rainfall.
Forecasts called for a first round of thunderstorms to hit downtown Chicago starting after 7 p.m., said Zachary Yak, a meteorologist with the National Weather Service. The threat of severe weather was expected to diminish as storms moved closer to the downtown area, Yak said. However, there will still be the threat of heavy rainfall, which could lead to localized flooding in some places, Yak said.
An initial round of storms was forecasted to clear out by 10 p.m., followed by a second round of showers expected to roll in starting around 11 p.m., Yak said. The National Weather Service anticipated that the second round of storms to continue overnight into Friday morning.
After a break, more storms were in the forecast for Friday afternoon, Yak said.
The bout of storms comes after torrential rainfall Tuesday night dumped nearly 5.5 inches of rain within 90 minutes, prompting reports of flooding in basements and viaducts on the city’s West Side.
tkenny@chicagotribune.com