Good Tuesday. After the morning fog burns off, we will have clouds building in through the day with one or two isolated showers this afternoon. Today's high will reach the upper 50s. The chance for rain will increase tonight. From 7pm on rain will be moving through widespread heavy at times. It will last through tomorrow afternoon and taper off tomorrow evening. Rainfall amounts tonight through Wednesday will range from 1"-2". Wednesday, even with the rain, will climb to about 64.
Thursday and Friday will be mostly cloudy with only a slight chance for a stray shower here and there. Lows will be in the mid to upper 40s and highs will be in the mid to upper 50s both Thursday and Friday.
Friday night another round of heavy rain will move in and last through at least the first half of Saturday. This will produce another 1" to 2" of rain widespread. If you are heading out for Christmas the best travel time will be either as early as you can Friday or as late as you can Saturday. Temps Saturday will be in the 50s all day.
Sunday we will finally see some cooler air moving in. Temps will range from 44 in the morning to 53 in the afternoon. Skies will be mostly cloudy.
The front bringing in the cooler air will stall to our south and even back northward a bit Sunday night into the overnight of Monday morning. As temps fall into the 30s as we head into Christmas morning I can't rule out some light mixed precipitation or even light snow between Midnight and 3am for areas east of Chattanooga.
Christmas Day will basically be cold. By the time you wake up any precipitation will be over and done with, and we will have cloudy skies during the early morning that will partially clear through the day. It will be in the 30s most of the day in Chattanooga, but we may touch 40 or 41 briefly during the afternoon. Basically, it will be a cold, dry Christmas. Christmas night into Tuesday morning temps will plummet into the 10s and 20s.