Updated: June 21, 2014 6:27PM
The National Weather Service issued flash flood and thunderstorm warnings for the Chicago area Saturday evening.
Just after 5:30 p.m., the NWS released a warning about flash floods in DuPage and Cook Counties until 11:30 p.m. Slow-moving thunderstorms in those areas were expected to bring “torrential” rainfall and affect urban areas and small streams.
In northwest suburban Buffalo Grove, over an inch and a half of rain fell in the span of 20 minutes, according to the NWS.
A “minor” flood advisory for Lake, Lee, Cook, De Kalb, Dupage, Kane, Ogle and McHenry counties was also in effect until 11 p.m.
About 5:45 p.m., the NWS also released a warning that Cook, Dupage, Grundy, Kane, Kendall and Will Counties could be hit with severe storms bringing quarter-sized hail and 60 mph winds. By 6 p.m., the warning for Cook, Dupage and Kane counties had expired, after the storm in those areas had “weakened below severe limits,” according to the NWS.
The NWS issued a severe thunderstorm watch Saturday afternoon for northeastern Illinois, including Chicago, until 9 p.m.
With an incoming jetstream and moisture entering the area from the south, conditions were favorable for severe thunderstorms Saturday in nearly 50 northern Illinois counties, including Cook, DuPage, Kane, Will and McHenry, according to NWS meteorologist Bill Nelson and the storm warning.
Though the storm warning was set to expire at 9 p.m., there was a 30 percent chance of more showers and thunderstorms overnight, with a chance for fog to develop, Nelson said. Temperatures Saturday night were expected to be in the mid-60s.