If you haven’t already, be sure and look up one of the many dramatic videos posted on YouTube of Sunday’s tornado in Hattiesburg, Miss. The tornado was rated EF-4, the second strongest level. Blessedly, no one died in the tornado, even though it tore into part of the University of Southern Mississippi campus. It may seem early for tornadoes, but mid to late winter is the start of tornado season along the Gulf Coast.
Though the wind advisory expires for western Virginia at 7 a.m., some breeziness will continue throughout Tuesday, but it will be mild with highs in the 50s as the westerly winds blowing down the Appalachian slopes compress and warm slightly. The fact that we’re not getting true Arctic or Canadian air out of this most recent cold front plays a significant role in our Wednesday weather.
The Hydrometeorological Prediction Center’s 1-inch snowfall map issued Monday evening, covering the time from 7 p.m. tonight to 7 p.m. Wednesday, delivers a pretty good idea of the current consensus expectations (as of late Monday) on where snow will be most likely with the next storm system. Guidance has generally closed on a track that will be somewhat south of us with the surface low, with the weak upper-level low tracking farther north. Generally, that’s a track that can lead to significant snow in our area, but there just isn’t much low-level cold air to support it, and the storm system does not appear to be dynamic enough to “create” its own cold air as we saw with the Jan. 17 snow and even last Thursday night locally over the Roanoke Valley. It will be razor-thin margin on Wednesday between cold rain and snow, and as we’ve seen lately, it’s easy to cross over that line. For now, the chances of snow are better the farther north and west you are relative to Roanoke, especially at 2,500 feet and higher elevations. Most locations from the Roanoke Valley and Blue Ridge north and west will probably see a little snow by Wednesday evening, but the chances of a widespread accumulating event appear to be low … for now. Stay tuned to forecasts, and keep an eye out the window Wednesday, just in case there are changes.
Some upper-level energy swinging around an eastern U.S. trough this weekend may trigger a snow event of some sort near or in our region. Forecast guidance is bouncing around with the specifics of that situation. One thing that will be much different than Wednesday is that the atmosphere will be much colder.