Happy Monday! While it wasn’t quite a winter wonderland, some of you received your first measurable snow of the season this morning! The average first snow (0.1″ or more) is later in December or even January in our area, so we’re a little ahead of schedule this year.
In case you missed it, Your Local Weather Authority is forecasting BELOW average snowfall this year in Southwest and Central Virginia.
Before I get to the seasonal snowfall projections, I want to start by explaining a few factors that are influencing this year’s forecast, like La Niña and Siberian snow cover.
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.
As many of you know, it’s been a season to remember in the Tropical Atlantic. There were 30 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.
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.
Here we go! For this winter 2020-2021, 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 on 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.
So after today’s marginal snow event, we still have most of this winter’s snow ahead of us!
You can always get specific forecast details for your zone, whether it’s the Roanoke Valley, Lynchburg area, Southside or elsewhere around Southwest and Central Virginia, anytime at WSLS.com/weather. Know your zone!
In case you missed it, we’re posting great weather and science content on WSLS.com. Here are a few links from the past week to check out:
-- Justin McKee