The gusty wind is bringing in extremely dry air, with dew points in the single digits, even below zero. It’s a good thing we’ve had 2 months of occasional rain and snow to soak into the ground, or we could be having a fire danger situation. The really cold air begins arriving Wednesday night with a cold front and upper-air disturbance that could trigger some rain and snow showers across Southwest Virginia, with some light accumulations possible in the typical upslope areas (near the Virginia-West Virginia border, west of I-77) and perhaps a few streaks farther east. Highs on Thursday and Friday are going to struggle mightily to even get to the low 40s — so enjoy tomorrow’s breezy mid 40s to low 50s as the “mild” day for a while.
A storm system is looking more likely this Palm Sunday weekend. With dense and unseasonable cold air blocked southward through much of the East, there’s a good chance at least some of it, and perhaps a substantial amount of it, will be frozen in our region. Forecast models today have seemed to be trending toward what we call a “Miller B” setup, with an inland low moving into the Tennessee or Ohio Valley, transferring energy to a coastal low along the Carolinas. The Monday morning weather map from the Weather Prediction Center (what used to be the Hydrometeorological Prediction Center) captures this baton-transfer pretty well. Normally, I would presume this would be a mostly rain situation for us because (1) it’s a Miller B, not an overrunning (moisture tossed over cold air from low that stays to the south) or Miller A (coastal low that originates from the Gulf of Mexico) setup, and (2) it’s late March. But the level of high pressure blocking in the northern latitudes is extreme, and this is going to force more far more cold air southward than we typically see this time of year. Despite the lateness on the calendar, the atmosphere actually looks to be colder overall than it was for the March 5-6 event that clocked the I-64 corridor and left lighter amounts in most of Southwest Virginia. So there is a good chance that any precipitation will at least start out as snow and/or sleet, especially if it arrives at night — and may end up that way, too, if the coastal low is strong enough to draw cold air southward in time. If the blocking is extreme enough to keep the original low more in Tennessee or farther south and then transfer to a new low off South Carolina, the chances that we have a primarily frozen precipitation event — perhaps even a mostly or all snow situation — would be better than if the inland low drifts as far north as what is shown in this weather map. These are among many details the forecast models are struggling to grasp at this early stage.
If you have weekend travel plans in or near our region, stay abreast of the forecasts for the potential of wintry precipitation in and near our region.