Steady to moderate rain has been falling over southern Wisconsin and northern Illinois Monday evening. These showers have been forming north of a warm front and low pressure system currently moving into west-central Illinois. The current cloud cover has kept the warm front draped across central Illinois and will limit how far it lifts north Monday night.
As low pressure moves further into Illinois late Monday evening widespread showers and thunderstorms are expected to develop, and have already begun to blossom over parts of Iowa and Illinois. The highest risk for strong to severe storms will most likely remain south of the immediate Stateline area, but could come close to parts of Whiteside, Lee and DeKalb counties. There, storms with gusty winds and heavy rainfall will be possible.
Further north the greater threat will most likely remain periods of heavy rainfall through Midnight. The rain coming down now will come to an end between 6pm and 7pm, but additional showers have already begun to develop to the southwest and will continue to lift northeast with the arrival of the low.