Wednesday, October 29, 2014 9:17 PM

East Coast Winter Storm Expected To Develop This Weekend

Matthew Holliday

Over the past couple of weeks, the forecast models have been in complete limbo. Even the European model, which is usually the model of choice for medium-range to long-range forecasting, has been all over the place in recent weeks. Initially, models had ridging building over the eastern United States to kick off November, which would have brought the area above average temperatures, but things made an 180 degree flip just a few days afterwards. I say that to point out that the atmosphere is acting in a way that has been difficult for models to handle, and it is showing in their outputs. I can’t say that I’m surprised, but that makes forecasting extra tricky. Once we get into the swing of winter, hopefully everything will get better. If you followed my forecasts at all last winter, you know that it’s common for me to disagree with forecast models especially in the medium and long-range.

What To Expect This Weekend: 

There is a trough that is going to develop and strength as it digs south over the eastern United States. A mid-level shortwave trough is then going to push south late this week and eventually close off as it makes it way to the Carolinas by this weekend. There is a strong model consensus that a surface low is going to develop over the Carolinas, and then strengthen off the Carolina coast. Now, don’t worry if you don’t understand any of the meteorology behind this.

Basically, this amplified trough is going to bring cold air with it. Areas such as the Great Lakes, the Ohio River Valley, the Tennessee Valley, the Southern Plains, the Southeast, and the East Coast will be experiencing the coldest air of the season so far this year. This is an impressive system for this time of year, although it’s not necessarily unprecedented. Places even into the panhandle of Florida will have temperatures dipping down into the 30s. You can expect areas further to the South experiencing their first freeze of the season this weekend. Strong winds can also be expected with this system, particularly in the mountains.

Expected Temperature Departures For Saturday

Expected Temperature Departures For Saturday

This will give you a taste of what I am expecting to come this winter. The weather across the United States will be volatile in November, meaning I don’t expect a cold pattern to set in for a long period of time for any particular region early on. I do expect wild swings in temperatures throughout the month, but I will discuss more about that in a few days.

What To Expect With This Winter Storm: 

Because there is a strong model consensus on the track of the upper-level feature that will be pushing south, it is hard for me to disagree with the overall track and where the surface low will develop. However, if for some reason the upper level low does not go as far south as forecast models are projecting, then we have a much bigger East Coast winter storm on our hands. At this point, I’m not ruling that possibility out.

Because the upper-level low is expected to push further south, the surface low pressure will be developing further south and eventually deepening along the Carolina coast. Now, the track of this system is key. If the current model projections verify, then this storm would produce a fairly decent snow event in the mountains, and amazingly, models even have enough cold air rushing in that there could be some wet snowflakes or snow showers outside of the mountains, possibly in the Charlotte area and even into northern South Carolina. Places even as far south as the southern Appalachians could get some snow.

Latest NAM Shows A Decent Snowfall Event In The Mountains

Latest NAM Shows A Decent Snowfall Event In The Mountains

Since this upper-level low is projected to go so far to the south, the surface low would stay far enough off the coast once it starts moving northward to prevent a major East Coast winter storm from taking place. Could this upper-level feature not go as far south? It’s possible, and future model runs need to be monitored just in case that were to occur. We would be dealing with a much bigger event along the East Coast if that were to happen.

Regardless, the mountains will most likely get their first big northwest-flow snow event, and places up in the Ohio Valley could see some snow. This low pressure eventually will move along the Northeast coast later in the weekend, and places like eastern Maine could get some pretty heavy snow.

So basically, storm track is pretty much everything. The cold air seems like it will be sufficient to support a winter storm, but how everything evolves will determine who gets what and how much. I always have a hard time trusting the forecast models particularly this time of year when we are entering the winter months and are in a transition phase. I always like to see how the models handle these pre-season storms.

Follow Firsthand Weather on Facebook: 

I will be posting future updates on any changes regarding the weekend winter storm on Facebook, so be sure to like the page if you haven’t already. If there were to be any significant changes, I will be posting a follow-up article, but otherwise, I will be working on Firsthand Weather’s final 2014-15 winter forecast that will be coming out this Sunday, November 2nd at 2 pm ET.