An upper level low will spin it's way southward from the Ohio Valley into Middle Tennessee today and remain about stationary through Tuesday.
After that, it slowly migrates westward but still remains close enough to supply above normal rain chances most of this week on its eastern side.
You can see the counter-clockwise spinning in this satellite animation:
Temperatures will be held down into the low 80s the next few days, and then slowly rise to the mid 80s.
Just when it gets far enough west to take us out of its influence, an influx of tropical moisture will push in from the southeast on Thursday & Friday, keeping rain chances high.