Want to be the first to see weather news? Sign up for our weekly email weather newsletter, featuring weather journalist Kevin Myatt.
A weather pattern that already seems to have spring in its step might slip into some slush briefly this weekend.
An upper-level low pressure system, essentially a southward dip of fast winds far above the surface, may be energetic yet slow enough to close off this weekend and become a tight swirl of cold air over our heads in Southwest and Southside Virginia.
Combined with a surface reflection of the circulation passing or developing to our south and east, and moderately strong high pressure over southeast Canada to push some colder surface air southward in the wake of a cold front interrupting this week’s mildness, there will be a window in which moisture may be lifted into a bubble of cold air and snow could develop on at least parts of our region, perhaps a fairly widespread area if the situation maximizes its potential.
Follow the latest on the developing weekend weather situation, @KevinMyattWx on Twitter or on the Kevin Myatt’s Weather Wonders Facebook page.
There are a lot of details to work out before the weekend about the specifics of how this system plays out, with Saturday night into Sunday as the most likely time for possible snow.
Wiggling a little north or south or east or west, being a little faster or slower, and other seemingly minute details of barometric pressure, humidity and temperature in various layers of the atmosphere can have significant effects on where and how much – and if – snow falls.
Air temperatures near the surface can always be problematic, especially in a winter like this one has been, as the cold air won’t be pooled up and waiting for the moisture.
Heavy or prolonged precipitation under and north of a closed upper-level low center this time of year usually coincides with, and partially enables, temperatures dropping to near the freezing mark and the atmosphere becoming cold enough for snow to reach the surface. Lighter precipitation, however, might occur with temperatures remaining a few degrees above freezing, leading to a cold light rain or “white rain,” or non-accumulating snow.
Heavier precipitation can also overcome warm ground temperatures by simply falling faster than the melt rate of the surface, developing a thin slush layer that continues melting slowly underneath while additional snow piles up on top of the slush. We often call this “wet snow.”
Higher elevations along and west of the Blue Ridge have the best chance of seeing accumulating snow this weekend, but other parts of Southwest and Southside Virginia could be in play for at least some slushy white depending on how this situation develops.
Atmospheric setups involving a closed upper low like this are notorious for dumping heavy amounts of wet snow in some locations while others not far away get little or stay rain. So it bears watching for more than just being a passing curiosity.
Such that it is, this is the best chance our region has had for a widespread accumulating snow this entire winter, but it would take a lot of moving parts coming into the right alignment for it to be more than just some “conversational flakes” at lower elevations.
That says as much about how few snow chances this winter has produced as it does about the potential of this particular system.
While it may be our instinct to label a situation that may wedge snow in between 60-degree weather 48 hours on either side “unusual” or even downright “weird,” atmospheric setups similar to this weekend are quite often how it rolls for snowfall in our region during February and March.
Two memorable snow events that immediately come to mind in the not-so-distant past would be those of March 30, 2003, and Feb. 19, 2012. In each case, temperatures were in the 60s or 70s the day before the snow, with the 2003 storm dumping 6-10 inches along and west of the Blue Ridge, breaking fully leafed tree limbs after a warm March, and the 2012 storm bringing 3-9 inches across just about all of Southwest and Southside Virginia, a breakthrough winter storm in a winter that was warmer than this one has been so far.
Though it was much earlier in the season, the Jan. 3 snowstorm last winter that snarled Intestate 95 fit the bill also. As you may recall, temperatures were in the 60s the day before over much of Virginia. Deepening low-pressure at the surface with a trailing upper-level low pulled the freezing level to the surface quickly.
Late March and early April of 1971 and late February 1989 were periods in Virginia in which temperatures were warm, then it snowed, then it got warm again, then it snowed again. Again, these were the result of dynamic cooling with individual upper-level lows passing through, not a prolonged pattern of frequently refreshing Arctic air.
Whether this weekend’s storm joins that list, and keeps several regional locations off various historic lists of almost non-existent snow, will be in the balance over the next few days.
One thing to stress is that, snow or no, this is not any kind of move to a colder weather pattern in the near-term or mid-range.
If a widespread snowfall happens, it will be a one-off, probably the last for at least two or three weeks and possibly for the rest of the season.
If it doesn’t happen, we’re right back to contemplating whether or not there will be a late February or early March winter redux to interrupt the near-snowlessness in much of our region outside higher elevations.
Many days will reach the 60s and some may top 70 over the next two weeks after this weekend.
Storm systems will move through with rain showers and some cooling from time to time, and there could even be severe thunderstorm outbreaks in the states west of us.
My strong advice to anyone who likes snow is, if you happen to see your surroundings whitened this weekend, enjoy it to the full as if it is the last time you will see snow until next winter. Because it just might be, especially if winter doesn’t return in March.
Some locations in our region, especially parts of the New River Valley and northern and eastern parts of Southside, saw a brief period of accumulating snow last Thursday (Feb. 2), but no more than 1.5 inches was reported, that coming at Eagle Rock in northern Botetourt County.
Most areas saw only cold rain, rain mixed with some slushy snowflakes, or a short period of “white rain,” also called “conversational flakes.”
Below is a list of reported snowfall totals for the season up to today in or barely outside Cardinal News territory, all well below normal:
Burkes Garden, 8.0; Bluefield, W.Va., 6.6; Lebanon, 2.0; Tazewell, 1.8; Radford, 1.0; Blacksburg 0.9; Richlands, 0.9; Tri-Cities Airport (Tenn., near Bristol, Va.) 0.6; Abingdon, 0.5; Wytheville, 0.5; Appomattox, 0.3; Glasgow, 0.3; Lynchburg 0.3; New Castle, 0.3; Saltville, 0.3; Copper Hill, 0.2; Covington, 0.1; Lexington, 0.1; Bedford, trace; Big Island, trace; Brookneal, trace; Buena Vista, trace; Danville, trace; Gathright Dam, trace; Hot Springs, trace; Pulaski, trace; Roanoke, trace; Rocky Mount, trace; Big Stone Gap, zero; Chatham, zero; Galax, zero; Martinsville, zero; Meadows of Dan, zero; South Boston, zero.
Journalist Kevin Myatt has been writing about weather for 19 years. His weekly column is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley.