National Weather Service United States Department of Commerce

We continue to monitor a potential for heavy rainfall, flash flooding, and renewed river flooding this weekend. A Flash Flood Watch is in effect for areas shaded in green on the Flash Flood graphic. From 7 PM tonight to 1 AM Monday morning where confidence in the heaviest rainfall is highest. Widespread rainfall amounts of 2 to 4 inches are expected, with localized amounts in excess of 5 inches possible through Sunday evening.
Rain will be seen more often than not across the area, especially northern Illinois, through the weekend. This includes some chances for embedded thunderstorms, a few that could be strong on Sunday along and east of I-55. The main message though is for periods of heavy rain that will raise flooding potential.