WDEF-TV News 12 Tennessee River Valley weather forecast Overnight: Mostly clear, chilly. Lows: mid/high 40's. Winds: SE @ 5 MPH. Saturday: Sunny, dry, warmer. Highs: low 80's. Winds: E @ 5-10 MPH. Overnight: Mostly clear, chilly. Lows: mid/high 40's. Winds:…