From the NWS

The image you see above is a new product the NWS is testing, it is called the thunderstorm percentage map... Pretty simple huh? The darker the orange gets the better of a chance of convective activity there is. Notice tomorrow the N TN and S KY area are pretty much in the 100% category..  We fall in the 70% category, but notice how the further south you go from the metro area the less the chance you have to see t-storms.. Cool huh? This is combining several factors: moisture, instability, lift, and a few other things.

Significant Tornado Parameter

Last night we had a pretty good night in terms of severe weather. The only warning we had in the state was for Floyd and Catoosa counties, plus we didn't even have any damage reports from anywhere. I would say that it was a nice night of just a few good old fashioned thunderstorms with some heavy rain in the early morning. I always know when it rains hard at night when I feel a little 8 year old creature climb into bed with me.. Such was the case last night which was why I was letting people at 4am know it was only heavy rain..... I was wondering so I am sure there were a lot of other people wondering. Anyway, lets talk about tomorrow.

Short Term

Showers and thunderstorms will be moving south today. The storms are not expected to reach the severe level, but there will be heavy rain, frequent lighting, and small hail.
Skies will gradually clear out this afternoon and temperatures will remain mild. We are starting in the 60s, and will reach the low 70s this afternoon.

The front that is moving south this morning will be moving back north as a warm front tonight. Clouds will increase and we will have a slight chance of showers overnight.

Long Term:

The next front will swing through the area late Friday into Saturday morning, bring the threat for strong to severe storms. High pressure will move in behind the front for Sunday and the beginning of next week.