A storm that AccuWeather meteorologists have been keeping tabs on for over a week is expected to trigger snow and slippery travel across parts of the southeastern United States from Thursday night to Friday night, but as is often the case, the heaviest snow is forecast to fall over the southern Appalachians, and milder air may limit wintry weather closer to the Atlantic coast.
"Marginal temperatures and a weak to moderate storm that continues to move along, rather than a strong, slow-moving storm, will play a role in keeping a lid on snowfall accumulations, especially outside of higher-elevation locations over the interior South with this storm," AccuWeather Senior Meteorologist Bill Deger said.
Air temperatures during much of the storm may hover above the freezing mark in some Piedmont locations.
"Snow can still fall at temperatures above freezing, but in this case, and especially so in the Southern states, it must snow at a fast and heavy rate to bring more than a light accumulation," Mr.
Deger said.
Areas to the northwest of the Interstate 85 corridor in North Carolina are expected to pick up 1 to 3 inches of snow, but areas to the southeast will have little to no snow accumulation. Conditions will change rapidly over a short distance around cities such as Charlotte and Raleigh, North Carolina, and Greenville, South Carolina. Rain or a rain and snow mix will occur to the southeast of these cities, while all snow or a wintry mix will fall to the northwest of these hubs.
Cities such as Asheville, N.C., and Bristol, Tn., can expect several inches of snow from the storm. The mountains in western North Carolina and eastern Tennessee are forecast to pick up 6-12 inches of snow with an AccuWeather Local StormMax of 18 inches over the peaks, such as Mount Mitchell and Grandfather Mountain in North Carolina.
Temperatures in the zone that will experience the heaviest snowfall during the storm will spend more time at or below the freezing mark.
The last storm that brought accumulating snow to the southern Appalachians struck on Christmas Eve and Christmas Day, with totals of 4.4 inches of snow in Bristol, Tennessee, and 2.1 inches of snow in Asheville, North Carolina.
As the late-week storm unfolds, some accumulating snow is forecast to dip as far south as the mountains of northern Georgia and the hills of northern Alabama.
Meanwhile, a rather sharp northern edge to the storm is likely to keep moderate snowfall away from places such as Roanoke and Danville, Va., where a coating to an inch of snow or less is anticipated. A similar accumulation is likely for Knoxville and Chattanooga, due to temperatures hovering above freezing during much of the storm.
Enough moisture and cold air may stop short of places such as Richmond, Va., and there is a significant chance that accumulating snow remains southwest of the city.
Motorists throughout the snowfall area, even where an accumulation under an inch is forecast, should be on the lookout for slippery conditions. Often with marginal temperatures, bridges, overpasses and areas shaded from the sun on a clear day are the first places to become slushy and slippery.
The same storm system will bring rain on its southern and eastern flanks. Even though the storm is forecast to move along at a steady pace and rainfall is likely to be under 2 inches, streams and rivers are already running high from prior storms this winter in the eastern parts of the Carolinas. This storm's rainfall can slow the rate of recession or lead to a secondary rise on some waterways.
Meanwhile, near the northeastern Gulf coast, the storm can pack enough punch for locally heavy and gusty thunderstorms later Thursday and Thursday night.
The risk of the storm swinging far enough to the north to bring any snow or a wintry mix to Washington, D.C., Philadelphia, New York City and Boston is much lower than forecasters had thought earlier this week. A dry end to the week and a dry weekend are projected for this portion of the I-95 corridor as meteorologists have much greater confidence that the storm will be out to sea when it makes a turn to the north.
AccuWeather forecasters will be watching the movement of a second storm that is expected to hit the South and could end up raising the risk of wintry conditions in the Northeast next week.
The next storm is forecast to spread moderate to heavy snow southward through the Rockies this weekend and into portions of New Mexico and western and central Texas on Sunday. This is the same storm that will bring heavy rain and mountain snow to the Northwest to end this week.
The weather pattern late next week and the following weekend has the potential to turn active with the risk of one or more storms turning northward along the Atlantic coast just as much colder air begins to flow southeastward from Canada. Major winter storms along the Eastern Seaboard and Appalachians often evolve from a setup like the one anticipated later this January.