The chance for snow continues to increase for parts of the South and Southeast early next week. An arctic cold front will move out of the Southern Plains into the South by Monday afternoon with temperatures quickly falling to near or below freezing behind the front. At the same time, an upper-level shortwave will move overhead. This shortwave combined with the vertical profile of the cold front will generate a strong upward motion in the atmosphere to allow precipitation to develop along and behind the cold front. Precipitation immediately behind the front will fall as rain Monday night and quickly transition to wet snow by Tuesday.
The first areas to experience snow will be far eastern Oklahoma, northeast Texas, Arkansas, western Tennessee and northern Louisiana by late Monday night. The rain & snow will move east and southward by early Tuesday morning into central Tennessee and parts of Mississippi (see Fig. 1) before moving further east into parts of Alabama and Georgia later on Tuesday (see Fig. 2). Parts of upstate South Carolina and North Carolina should get in on the rain & snow later in the day on Tuesday.
While this is not a setup that climatologically produces major snow events, it increasing in likelihood that accumulations are likely. The event being a few days out makes it extremely difficult to forecast snow accumulations. There are two big negative factors for accumulations. I) Monday (the day before the snow) will be warm across this region, which will lead to warmer ground temperatures, and II) the window for snow is only about a 4-6 hour period. With that said, this does appear to be the best chance so far this season for accumulating snow across the South and Southeast. The snow rates should exceed melting and the best chance for accumulations will across northern & central Mississippi, Tennessee, northern & central Alabama, northern Louisiana and northern Georgia. Guidance is evening indicating some instability, which could lead to convective banding of snow. This could dump heavy snow amounts for isolated locations. It is too difficult to pinpoint where those bands may setup. That is almost a nowcasting scenario. Secondly, areas that see snow pre-dawn on Tuesday will have the best chance to see accumulations and nasty road conditions. Even though it is difficult to forecast snow accumulations this far out, I wanted to provide you with a preliminary snow accumulations map (see Fig. 3). Please note, this will likely change over the next 48-72 hours as we get closer to the event. It is possible the polygons may need to me reduced or expanded, and snow totals may need to be increased or decreased.
Christopher Nunley is Meteorologist on Firsthand Weather, Lecturer in the Department of Geosciences at Mississippi State University (MSU), and a PhD Candidate (Earth and Atmospheric Sciences) at MSU. He earned his M.S. in Applied Meteorology at MSU, was an Assistant Cross Country Coach and taught at the University of North Texas, and was a Broadcast Meteorologist at KTEN-TV (just north of Dallas, Texas). Christopher’s main focus lies within teaching and inspiring prospective meteorology students, atmospheric research to further our understanding of atmospheric processes, and forecasting and analyzing extreme weather events to help save lives!