The change has been coming for a while. The cooler air has been bottled up and now it is on the way into Kentucky. We'll see daytime highs come tumbling down on Thursday/Friday. It looks like Wednesday will be more of a transitional day. A frontal boundary will be swinging through Kentucky and bring the change.
The blast from the West will shave about 10-15 degrees off of daytime highs. The rain chances will increase on Thursday and quickly dry back up by Friday. It will make for a nice weekend, but a little cooler.
I'll have more details!