Wow! Huge difference in temperatures on this map. Cooler air will pour in to Indiana Thursday.
Wednesday will feature plenty of dry hours but expect rain on and off throughout the day--enough that you'll need an umbrella.
We've had remarkably high moisture content lately, as seen in the dew points. That moisture will drain with the passing of the boundary this week. Much drier air will dominate through the weekend.
Highs today will near 80. It will be a little breezy but certainly will still feel warm.
The cold will explode in Thursday and beyond. We should have a few dry days until the second half of the weekend.