National Weather Service United States Department of Commerce

Sunshine will return to central Illinois on Sunday and Monday, but conditions will remain on the cool side. Afternoon high temperatures will only be in the 60s, while overnight lows dip into the 40s and 50s. After that, a slow-moving storm system will pivot into the region from the southwest. This will lead to a prolonged period of showery weather starting Tuesday and lingering through Thursday. While it will not rain for that entire time, it appears the heaviest and steadiest rains will be most likely Tuesday night into Wednesday.
3pm radar imagery showed another round of showers and thunderstorms developing across central Missouri into southwest Illinois. This activity will track northeastward along the I-70 corridor for the remainder of the afternoon into the evening. While severe weather chances will remain low, additional rainfall on already wet soils may lead to localized flash flooding. The rain will gradually taper off toward midnight.