Some light freezing rain could occur Monday morning, just as we’re shrugging off the arctic grip that Mother Nature has had on us for the past week.
It doesn’t look like anything too significant at the moment, but as cold as the ground is going to be — even though temps are expected to warm to above freezing Sunday afternoon — even a little precipitation could cause some travel issues.
The National Weather Service’s Morristown weather field office is currently forecasting a 50 percent chance of a wintry mix of sleet and freezing rain Sunday night, with a low temperature of 31 degrees.
The latest run of the GFS forecast model has us dropping very briefly to 31 degrees early Monday morning, just as light precipitation is beginning to move into the region. However, model output statistics from the same model run — which weigh the raw data against other factors in an effort to create a more reasonable depiction of what our weather might be — drop us only to 37 degrees during the overnight hours. Obviously, freezing rain won’t be a concern at 37 degrees.
Other models, though, are cooler than the GFS. Most notably, perhaps, the NAM forecast model drops us to around 28 degrees at daybreak, with light precipitation moving in. The Canadian model is very similar to the GFS.
Winds will be out of the south, which is why we’ll see our temperatures climb well into the 40s on Sunday. That warm air advection is tough to hold at bay — particularly here on the plateau, where we aren’t sheltered by terrain features — and often proves stronger than models indicate.
The chance for some very light freezing rain will probably be greater in the valley locations to our east. That’s where the warm air advection will have a more difficult time eroding all of the cold air Sunday night. The plateau to the west and the mountains to the east will help shelter the valley, and cold air tends to have a pooling effect in valleys. That’s why, on fall or winter nights when the southerly winds are kicking up, we are usually warmer in Oneida and Crossville than they are in Knoxville — whereas on a normal morning, without the southerly winds, higher elevations are almost always colder than lower elevations.
As long as the NWS is forecasting temps to drop just below freezing with light precipitation in the area, it’s worth keeping an eye on. My guess is temps struggle to get below freezing here on the plateau Sunday night, and precipitation may hold off until later in the morning, anyway, depending on how slow the air mass is to saturate. But those are questions that will be answered more definitively in the coming days.
Eye to the Sky is a weather blog by Independent Herald editor Ben Garrett. Garrett is a weather enthusiast who has long blogged about interesting weather on his personal website. He is not a professional forecaster or a meteorologist and information on this blog should not be considered a substitute for forecasts, advisories or other products from the National Weather Service.