This past weekend, there was a buzz about snow on social media.
Some forecast model runs depicted a fairly idealized setup for a large winter storm to form over the Eastern U.S. a few days before Christmas, while others were only a tick or two off.
However, the excitement has subsided as it becomes more obvious, as we move closer to the coming weekend, that the next Arctic punch of what has been a pretty cold December will come in, like its predecessors, mostly dry.
After Tuesday’s latest warm spike, temperatures will return to highs in the 30s and 40s and lows in the teens and 20s through the coming weekend and into the first day or two of Christmas week.
There will be a couple of impulses diving southeastward in the northwest flow. Theoretically, one of these could lift enough moisture for a band of snow to develop or even help spin out a surface low over the South or near the East Coast. However, there are just enough loose screws in this scenario to expect that the window will slide closed and that there will be no widespread pre-holiday snow of some inches in Southwest and Southside Virginia or quite likely over almost all of the Eastern U.S.
As has happened previously, the cold air shot is transient, being pushed out in this case by a continental warmup arriving here just after Christmas, and the associated upper-level trough is centered too far east for optimal winter storm development near us. We’re getting mostly dry northwest flow with no Gulf of Mexico or Atlantic moisture influence while it’s cold.
After a mild, damp first three days of this week, it will quite likely be cold and mostly dry in the days leading up to Christmas. There might be some snow showers blowing over the mountains over the weekend, as is typical with any winter cold front, but a Bing Crosby-quality white Christmas snow looks unlikely.
How you feel about that will vary; many people do dream of a white Christmas, which occurs about once every 10 years in much of our region. (I plan to look back at some of those in next week’s Cardinal Weather column, coming out a day early on Christmas Eve.) Others would just as soon skip it and be able to get to grandma’s house without slipping and sliding around.
What’s more, a big warmup starts with possibly some rain showers on Christmas itself, and many of the days between Christmas and New Year are likely to be quite warm, 60s and maybe 70s for highs. You will be able to get outside and play with some of the new toys you opened.
Winter storm ‘windows’
When I’m looking at the weather pattern beyond three days ahead, I’m not so much looking literally at what forecast model data shows happening with surface features, as that will shift back and forth wildly. Instead, I’m looking for windows of opportunity for winter storms, when the overall pattern could be supportive of significant snow or ice or mixed precipitation for our region with only a couple of nudges in projected weather features.
Despite multiple cold shots that are tilting December temperatures below normal, we haven’t really had any such winter storm windows yet.
Yeah, there was some freezing rain and sleet on Sunday sprinkled within a broad area of cold rain, but there wasn’t much about that setup that screamed widespread winter storm with the low-pressure center passing hundreds of miles northwest of our region.
Also, the upslope-enhanced snow in our western rim areas that happens behind almost every cold front doesn’t count here, unless it is part of a broader storm system spreading fairly widespread and significant snow or wintry mix to at least the Blue Ridge.
Winters are not created equal in the number of potential winter storm windows they produce, nor in how many of those end up producing. You might think of this like winter storm “at-bats” with the ones that happen being “hits.”
Last four winters
Last winter, I count at least six such windows that produced only once — a paltry .167 if it were a baseball batting average. The only hit was the Martin Luther King Jr. Day snow that covered all of our region except Southside with anywhere from 1 to 8 inches of snow, with a couple of larger amounts in the highest elevations west of Interstate 77.
Other than that, last winter had a near-perfect coastal low track that was almost totally bereft of cold air on Dec. 17; a low that cut just a little too far west and left us with mostly patchy ice on Jan. 6; weak lows on Jan. 19 and Feb. 17 during brief cold spells that went a little too far north; and an upper-level low seemingly tracking perfectly out of the Desert Southwest, with cold air oozing in from the north, that somehow managed to get suppressed all the way to the middle Gulf of Mexico and Florida in early February. Those account for five missed windows for winter storm potential.
Throw in two powerful lows that tracked well northwest of our region on Jan. 9 and Jan. 12 — the type of big wet lows expected in El Niño but tracking inland, keeping us on the warm side, instead of going up the coast, putting us on the cold side — and that was pretty much the ball game for why last winter undershot many bountiful snowfall forecasts.
Two winters ago, in our almost-snowless 2022-23 winter, there was really only one serious window for a winter storm, on Super Bowl Sunday, Feb. 12. That was a storm system that in every way would have been a significant to major winter storm for our region if there had been a pool of even modest surface cold air to be pulled into it. Instead, being true to the theme of that winter, it somehow managed to underperform even its already reduced forecasts, leaving the New River Valley virtually snowless while only producing a streaky narrow stripe of 1-5 inches of snow in Southwest Virginia as far east as Fancy Gap and southern Floyd County. This only happened because it was able to import some cold air from the high in the atmosphere on the storm system’s back side after a soggy Sunday.
I won’t recap every single winter going back in time, but the 2021-22 winter was pretty good at maximizing its limited opportunities, with two sizable snow events (generally 3-10 inches in both over most of the region) and a couple of smaller ones, mostly compacted into a cold January. Not many winter storm windows were missed three winters ago.
The 2020-21 winter was a different animal altogether, with seemingly almost constant light to moderate wintry precipitation threats all season, most of which partly verified with mixed precipitation, some ice or small amounts of wet snow. Only a couple of the windows turned into 4-8-inch type snows over large parts of our region, and there was a big power-crashing ice storm in parts of Southside on Feb. 13. I haven’t counted, but there might have been a dozen or more winter storm “at-bats” in 2020-21, most turning into long pop flies and groundouts rather than strikeouts.
It’s not quite true that we quit having winter after the big early December snowstorm in 2018. We’ve just been having it less often.
Changing winters?
There are long-term factors related to a warming global climate that can come into play here, possibly reducing the frequency of windows for possible winter storms through overall milder temperatures on average, less frequent and/or less deep Arctic air intrusions, or possibly changes in the atmospheric wind patterns that can connect the moisture and cold air.
We pondered natural variability vs. climate change last March specifically regarding the post-2018 lull in snowfall our region has experienced.
But, to be fair, a warmer climate might also offer the potential for more moisture to infuse some winter storm setups, leading to deeper snow or thicker ice than would have otherwise occurred in some storms. Or, sometimes, cold air masses can get trapped longer farther to the south as temperatures warm at far northern latitudes (think Texas power grid nearly freezing solid in February 2021).
So, it’s complicated.
Every winter for several decades has produced at least one reasonable shot at a significant widespread winter storm in our region, with varying degrees of how well those being manifest year to year.
There’s no reason to expect that there won’t continue to be these windows of potential in virtually every winter for the next couple of decades, at least, even with some additional planetary warming.
I fully expect to see one or more serious windows for a possible winter storm in January and February. How those at-bats play out will determine how the 2024-25 winter is remembered.
But it doesn’t look like this will happen on this weekend before Christmas nor in the remainder of 2024.
Journalist Kevin Myatt has been writing about weather for 20 years. His weekly column, appearing on Wednesdays, is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley. Sign up for his weekly newsletter:
