Rain is in the forecast for the weekend, but it will not be a washout and there should be many dry hours Friday and Saturday.
Low pressure will lift northeast out of the south-central Plains during the day Friday. As it does, it'll pull a warm front from central Illinois into Wisconsin by Friday night. With the arrival of the front, showers and thunderstorms will increase in coverage through late afternoon and evening. Severe weather is not expected, but heavier rain could fall with any of the thunderstorms.
The majority of Saturday is looking to be dry with just an isolated shower/storm chance during the day. Storm coverage will increase west of the Mississippi River ahead of a cold front that will move southeast from the northern Plains. Dew points Saturday will climb close to 60 degrees and with the passage of the cold front there could be a few stronger storms over parts of northwest Illinois Saturday evening. While the overall threat for severe weather locally remains low, there could be a few stronger wind producing storms. So make sure you pay close attention to the forecast, especially if you're going to be out, over the weekend.
By Sunday the cold front will be moving south of Rockford bringing an end to the rain.