The National Weather Service has issued a flash flood warning until 8:45 p.m. Tuesday for parts of west central McHenry County in the Marengo area, as well as parts of eastern Boone County.
People in that area should move to higher ground and avoid walking or driving through floodwaters, the weather service advises.
That followed an earlier “special weather statement” that expired at 5:30 p.m. Tuesday for Woodstock, Marengo and parts of Bull Valley and Huntley.
Though that threat has expired, the weather service said an ongoing cluster of thunderstorms in northern Illinois will continue to drift south into the Chicago area with a threat of gusty winds and small “non-damaging” hail and which could produce lightning and downpours. That threat continues through 8 p.m. Tuesday, the NWS reported.