WDEF-TV News 12 Tennessee River Valley weather forecast Overnight: Mostly clear. Dry. Chilly. Lows: high 40's. Winds: Light/variable. Monday: Sunny, dry, warmer. Highs: high 70's. Winds: W @ 5 MPH. Overnight:Mostly clear. Dry. Chilly. Lows: mid 50's.  Winds: S @…