A powerful cold front is racing towards East Tennessee, pulling with it an arctic air mass that is more typical of January than November, and that means the region’s first true taste of winter is likely in store for the first half of the work week.
There will even be the possibility of the region’s first accumulating snow — albeit a light one — as a limited amount of moisture accompanies the cold front late Monday night and early Tuesday morning. In fact, the potential for a few snowflakes dancing around and rapidly crashing temperatures has some local students daring to dream of a snow day — an extreme rarity in November — on Tuesday, when schools are set to re-open after a three-day Veterans Day weekend.
For the record, the chances of enough snow to cause road conditions to deteriorate on Tuesday are quite slim. But, on the opposite side of the coin, those chances aren’t completely non-existent — although precipitation will be very limited and ground conditions will be quite warm.
The latest forecast for Oneida from the National Weather Service is for a 90 percent chance of rain changing to snow Monday night, and a 60 percent chance of snow early Tuesday morning, though snow chances will quickly end as the day begins.
While forecasters still aren’t certain on the exact timing of a transition from rain to snow, the NWS’s Morristown weather forecast office said in a discussion Sunday afternoon that the current thinking is that the changeover could occur as early as 1 a.m. Tuesday morning, with light to moderate snow continuing through 6 a.m. before tapering off to flurries that will continue through late morning or early afternoon. The NWS said in the discussion that “most areas will see anywhere from a trace up to half an inch (of snow).”
Forecasters at Morristown acknowledged that models are showing more accumulation than that, but said their forecast undercuts those amounts due to the fact that high temperatures will be in the 60s on Monday — leading to warm ground temperatures being in place as the period of light snow arrives later that night.
In its forecast discussion for Fentress County and the western side of the northern Cumberland Plateau, the NWS’s Nashville weather forecast office was a bit more detailed in what to expect. Like meteorologists at Morristown, those at Nashville undercut snow accumulation forecasts due to warm ground temperatures; however, they said up to an inch of snow is possible along the northern plateau.
While road conditions will be okay across most of Middle Tennessee, forecasters there said, travel impacts will be more dependent on snow totals on the northern plateau. “I would not be surprised to hear snow reports of a little better than an inch by daybreak Tuesday, which could lead to at least some minor travel impacts,” the discussion read.
While most of the minor accumulations that do result Tuesday morning are likely to be limited to rooftops and grassy surfaces, freezing and black ice could be an issue on bridges and overpasses if the gusty winds that accompany the frontal passage do not dry off those surfaces quickly as temperatures crash.
The current projection from one model — the GFS, a global computer guidance model operated by the NWS — is for temperatures along the northern plateau to drop from 45 degrees at 10 p.m. to 32 degrees at 1 a.m., and to continue dropping to 26 degrees by 7 a.m. while struggling to rise much once the sun rises Tuesday morning.
Temperatures on Tuesday night are likely to approach record territory — the current forecast from the NWS is for a low of 15; the record is 11, set in 1976 — and wind chill values could drop into the single digits on Wednesday morning.
Tuesday’s record low daytime temperature is likely to be smashed; the current record in Oneida is 37 degrees, set in 1996. The high on Tuesday is unlikely to get out of the 20s. However, the official high will be the temperature recorded at 12:01 a.m., when temperatures will likely still be above freezing as the colder air mass moves in.