Tuesday brings the likelihood of another messy wintry precipitation episode to much of Cardinal News’ Southwest and Southside Virginia coverage area, and by extension, most of Virginia.
Winter storm watches have been posted for most of Virginia, excluding the southwest and southeast corners, for a wintry mix of snow, sleet and freezing rain. These are likely to become winter storm warnings or winter weather advisories by Monday evening, depending on how later data affects projected amounts of snow and ice.
A full-blown snowstorm with several inches of snow appears likely for much of the northern half of the state. Farther south, due to several variable factors including onset time, depth of cold air aloft and at the surface and intensity and timing of milder air surging in aloft, it gets far more complicated with great potential for a “bust” or “boom” storm — missing projected inch ranges low or high — compared to whatever forecast you may look at from whatever source, including this one.
Precipitation is expected to begin as snow across much of this area and then change to a mixture of freezing rain, sleet and rain from the south and southwest as the day goes along, ending snow accumulation but continuing wintry travel issues and potentially damaging ice accumulations in some areas.
Across our region, snowfall is expected to range from less than an inch along the southern border and in the southwest corner to near 6 inches in some areas north of the U.S. 460 corridor and toward Interstate 64. Ice accretions on top of snow and some crusty sleet could top a quarter-inch in some areas, especially near the Blue Ridge.
While there are signals down the road that Arctic air may surge back into the central and eastern U.S. for a prolonged period in the latter half of February, this is not that. Tuesday provides only a brief window when colder air surging southward will be trapped against the mountains in sufficient depth for the potential of snow as a wave of upper-level low pressure moves eastward. Surface temperatures will be marginal, near the freezing mark, so this will tend to be a slushier storm than what happened with the somewhat similar snow/sleet/ice event on Jan. 5-6.
This colder air will be scoured out, and additional precipitation systems the remainder of the week and weekend are likely to be mostly rain, except possibly some freezing rain in some western and northern areas of Virginia on Wednesday night and early Thursday. Flooding is a larger concern than wintry precipitation in states west and southwest of us with this week’s train of storms, and not out of the question for Virginia by the weekend.
Precipitation is expected to spread across Southwest Virginia from the west in the pre-dawn hours of Tuesday morning, reaching areas east of the Blue Ridge near or shortly after sunrise. It is expected to start as snow in most locations, though the changeover to mostly rain or freezing rain may be very quick in the southwest corner and areas near the North Carolina border where milder air aloft is less impeded outside the cold-air damming wedge.
East of I-77, and north of the North Carolina border counties, where cold air is likely to be wedged against the mountains more deeply, snow will last longer. How long and how heavily it falls as snow before changing to a mix is the sticking point on how much will accumulate. Temperature differences related to elevation, plus streaks of heavier and lighter snow could also create up and down variance in local areas.
A faster surge of warmth aloft could reduce snowfall totals, while slower warm air advection or a more stubborn resistance of cold air damming could lead to longer snowfall and greater amounts. Various computer forecast models have shown each of these outcomes as possible, with most clustering toward the middle of the extremes.
This is a situation not to focus on precise amounts or be shocked if it’s somewhat under or over whatever forecast range you see on any weather source. Do plan for the likelihood of some slushy, icy or snow-covered road impacts early Tuesday.
Later in the day, some locations, especially along the Blue Ridge south of Roanoke, may collect enough ice for sagging tree limbs and possibly scattered power outages. There may be additional risk of ice occurring late Wednesday and early Thursday.
As usual in marginal wintry precipitation episodes across varied terrain, do not presume that conditions outside your house are exactly like those you may encounter even traveling just a few miles away.
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: