The National Weather Service warns that temperatures in Chattanooga could plummet to a low of 27 degrees on Thursday, bringing a 20 percent chance of snow in the evening.
Lows in the 20s are also expected on Friday and Saturday, though daytime temperatures on Thursday, Friday and Saturday are expected to rise above freezing.
The snow alert is part of a week of hazardous weather that the federal agency warns will begin with strong thunderstorms, heavy rains and damaging winds late today.
According to the agency's hazardous weather outlook issued this morning, "a much colder airmass will move into the southern Appalachians and eastern Tennessee valley region by Wednesday night and continue through the weekend."
"Moisture moving over the cold air will bring some snowfall to the area," the agency said.
The service may activate its network of spotters to confirm reports of snowfall on Thursday.