Heavy rain will be the issue through the first half of the day. Significant snow & sleet will be the call during the afternoon through tomorrow. Look for almost impassable travel in some spots tomorrow.
The heat kicked back in for many of us during the afternoon on Saturday. It has one more solid run for Sunday. The catch with Sunday is that we'll not only have the heat, but the possibility of strong or even severe storms during the afternoon and evening.
A line of thunderstorms likely develops during that afternoon across Illinois, Indiana, and Ohio. These storms will track southward into Kentucky. The main concern from these thunderstorms will be the strong winds. There is a ton of cold air behind this system and it will help force strong winds through the line. Many sections of the line will start bowing out. That suggests we'll see very strong winds pushing the line along. With this much wind pushing the line, some of these storms might even have a little spin associated with them. That means an isolated tornado can't be ruled out.
The end result means some much cooler air will filter in behind the front. Fall like temps will filter back into the region. It will feel absolutely wonderful. We'll just have to pay a high price to get there.