Wednesday, January 20, 2016 9:59 PM

Everything You Need To Know About This Upcoming Winter Storm

Matthew Holliday

As promised, I will keep this article brief and to the point. I have provided you with a lot of details on this upcoming winter storm already, but given that I have put out numerous updates on social media and the website at different times, I’m sure some of you have missed some important information.

Just to reiterate, a lot hasn’t changed with my overall forecast. This winter storm will be a significant winter storm for many across the United States, and it is definitely showing similar characteristics to some of the historic winter storms of the past. Overall, the forecast model guidance is in agreement other than on some of the specifics. The European model came in slightly north with its overall track and the GFS jogged slightly south. Surprisingly, I’m not in strong disagreement with the actual track that the models take this system. With that said, a jog as little as 25-50 miles north or south can make a HUGE difference, so be aware of that.

Okay, take special note of all the bullet points that I listed below:

• Snow/sleet will fall across northern Mississippi, eastern Arkansas, western Tennessee, and possibly as far south as extreme northern Louisiana on Friday. Many of those regions will start out as rain, but the transition to frozen precipitation will occur on Friday. Accumulating snow, which could be locally high in places, could fall especially across the northern third of Mississippi, the eastern third of Arkansas, and western Tennessee. Some accumulations will be possible in the other regions mentioned, too.
• A stout warm nose will be present just above the surface, extending across much of Alabama, Georgia, and eastern Tennessee. This will originally cause most of the area to start out as a cold rain, but a transition to snow/sleet will eventually occur. This will cut down on overall snowfall accumulations, but regions as far south as Atlanta and Birmingham could get some accumulating snow once the transition occurs. The heavier accumulations should occur just north of those bigger cities.
• As I have mentioned several times, there will likely be a cold air damming scenario that sets up as far south as northeast Georgia and Upstate and northern South Carolina. I expect a potentially significant ice storm (accumulations of ¼ inch of ice) to unfold across these regions starting on Friday. High ice accumulations will likely also occur across central and eastern North Carolina (likely excluding the near coastal regions). Forecast models tend to handle these scenarios horribly, but I have noticed that the guidance is handling this well today. Models could be slightly underestimating how far south this freezing rain falls. Please read the next bullet point.

Probability of greater than 1/4 inches of ice accumulations from Thursday night to Friday night:

Ice Storm Probability

• A transition to snow will eventually occur across most of the regions mentioned in the last bullet point, and the heavier accumulations will fall the farther north one goes. Snow could fall as far south as Midlands SC, but accumulating snow will be higher the farther north was one goes. I can’t even rule out some snow falling along the northern South Carolina coastal regions and near the North Carolina coast, as the cold air rushes in behind this system and moisture gets wrapped around the coastal low.
• The bullseye of very heaviest snowfall accumulations will likely fall from Kentucky into West Virginia and Virginia, including the Washington, D.C./Baltimore areas, southeastern Pennsylvania, including Philadelphia, Maryland, Delaware, and New Jersey. A region of heavy accumulations could also fall in western and north-central regions of North Carolina. This is going to be an extremely close call for New York City and Long Island, as a slight shift southward in track will remove NYC and Long Island from seeing as high of snowfall amounts. Many of these areas will be measuring snow in feet.
• Extreme southern regions of the Ohio Valley could get accumulating snow from this system, too.

Probability of greater than 4 inches of snow falling from Thursday night to Friday night (probabilities for amounts lower than 4 inches aren’t included):

snow prob map 1

Probability of greater than 4 inches of snow falling from Friday night to Saturday night (probabilities for amounts lower than 4 inches aren’t included):

snow prob map 2

I including every region that could possibly be impacted by this system. If you are on the edges of any of the regions that I just mention, be aware that a slight jog 25 miles north or south could be the difference between getting snow accumulations or very little snow at all. Also, as energy gets transferred to the coast, a dry slot will probably eventually set up somewhere. Keyword SOMEWHERE. Nailing that down will be pretty difficult, and wherever this sets up, this could cut down on overall accumulations for some of you.

Overall, I’m very pleased with the forecast. Hopefully this clears up some of your questions. Most of you are well-aware of how a slight change in track could change the forecast significantly for some of you, especially if you’re on those borderline zones. I will have continuous coverage tomorrow on this winter storm.

By the way, the image used as the feature image in this article was from last winter, taken in Grafton, MA by Sevag Sarkisian. I figured it was fitting for this article!