ROANOKE, Va. – Since July, we’ve been asked what this winter would be like and while long-range forecasting is difficult and lacks the precision of a day-to-day forecast, Your Local Weather Authority has worked hard to create this forecast of what we will see in the coming months.
Before our snowfall projections, we want to start by explaining a few factors that are influencing this year’s forecast, like La Niña and Siberian snow cover.
La Niña
One thing to look at closely is the El Niño Southern Oscillation. This year, we are dealing with La Niña conditions, which are described as cooler than average temperatures in the Pacific Ocean, off the coast of Perú.
In the Southeastern United States, we usually experience warmer and drier conditions during a La Niña winter. Wetter (or snowier) than usual conditions are expected in the Great Lake states and Pacific Northwest, while it may be cooler than average in the upper Midwest.
Our own research has shown us that 74% of winters during a La Niña year have brought us below-average snowfall; however, that’s not to say we won’t see any snow.
Tropics
As many of you know, it’s been a season to remember in the Tropical Atlantic. As of this article, there have been 29 named storms this year, breaking the record of 28 from 2005.
The tropics have an inverse effect on how active winter is in the Eastern United States.
Storms transfer energy toward the poles and if more energy is used during hurricane season, less has to be spent during winter.
It’s been an above-average year in the tropics, thus our forecast calls for a below-average winter.
Siberian Snow Cover
We’ve talked about the role that oceans play, but there’s also a role that snow in Siberia plays in a seasonal forecast in the Eastern United States.
Over the past few weeks, the snow has expanded in Siberia, snow reflects light. That process warms up the stratosphere, the layer of air above us.
That would favor more frequent pulses or snaps of colder air, so we’re looking at the first half of winter being colder than the second.
2020-2021 Snow Outlook
Here we go! For this winter 20-2021, we are forecasting below-average snowfall totals.
Let’s break this down by telling you which areas we’re forecasting will get the most snow down to where they won’t see that much this winter.
As you would expect, the Highlands are probably going to see the most snow, 16-22 inches. That is for Highland and Bath counties, as well as Pocahontas and Greenbrier counties in West Virginia.
Whitetop, Snowshoe and Mountain Lake will likely receive more than the numbers shown in white on the map.
In the New River Valley and Mountain Empire, we’re forecasting 13-19 inches of snow.
If you live in Roanoke, Lexington, Covington, Clifton Forge Botetourt County, Franklin County or Patrick County, you can expect 9-15 inches of snow.
Areas in and around Lynchburg are looking at 6 to 12 inches of snow, while Southside locations like Martinsville and Danville will receive 2 to 8 inches of snow.
How does this compare to average? Based off historical data, Southside receives 8 inches of snow and Lynchburg gets 15 inches.
Roanoke’s average snowfall is 18.5 inches, while the New River Valley gets 22 inches and the Highlands receives 24 inches of snow.