RICHMOND, Va. (WRIC) — It is time for my 34th annual winter forecast for Central Virginia. In the past two years, we have enjoyed some very warm winters here in the area. Yes, we have had snow…and some good snow. But those were both basically “one and done” events for us. Basically, one storm (2016’s was a humdinger) supplied just about all of our snow for the winter.
This year it does not look like we will make it three in a row. Things look to be changing, and you won’t be as fortunate this year from what I can see.
There are a lot of factors to talk about that will be affecting our forecast throughout the winter—you need to look at a lot of stuff, but I want to touch on a few of them for you.
First up, it’s the La Nina/El Nino pattern. Yes, that is the area thousands of miles away from us in the tropical Pacific that drives where the jet stream is going to be. This year I am expecting a weak La Nina which is a cold pattern in that area. How does it affect us? Well, this drives the position of the jet stream. It allows for a “ridge” (upper-level high pressure) over the west and a “trough” (just the opposite) over the east. That sets the stage for cold air to be delivered into the eastern part of the nation. Since this is a weaker La Nina, the cold air may not come screaming south at us—the brunt should be in the Great Lakes—but it’s enough to where things are going to be cooler.
In the Atlantic, I watch the North Atlantic Oscillation. When it is “positive” it keeps much of the cold weather away from us. In the “negative” phase, it is a favorable condition for snowstorms in the east. In fact, if you look at a history of the “NAO Index” when it shows negative has often coincided with snow winters for us here. This year I look for it to be weakly negative—a good sign for snow, but not screaming “falling like lard” for us here.
Finally, there is the Arctic Oscillation, which is the area around the North Pole. If you have been following climate science at all, you probably have heard that the Arctic is one of the fastest warming areas on the earth. And that the ice cap keeps reaching new lows in summertime coverage. Well, what a warmer arctic does is 2 things. First, it helps to create a stronger pool of cold air just to the south in the “sub-arctic” region. That’s what can be tapped into and drawn down over us. Secondly, when the Arctic Ocean freezes over, it releases a lot of latent heat into the atmosphere which helps warm this up—and what in the past two years has really caused our coldest weather of the winter to come very late—long after the ice has formed.
As meteorologists, we like to look for “analogs” or comparison years with similar weather patterns to try and forecast using past history. Here are some of the years that I see comparable to ours
1984-1985. Not really much in the way of snow, but brutally cold January temperatures
1995-1996. A very active tropical year that led to active winter storms in the northeast and here
2010-2011. Not “Snowmaggedon”—that was the year before, but an active December
2013-3014. “The Polar Vortex” very cold air over the Midwest and northeast
With that in mind, here is what I am expecting for this year
A.) The two primary storm tracks will be an “Alberta Clipper” on that comes right over us. Similar to ’84-’85. If we can get a strong clipper to cross to the south of us, it could deliver some brutally cold air into the region
B.) The second track will be what is called the “Inside Runner” at it will favor storms up the Appalachians. We are on the east side of that track, which is more of an ice risk than a snow risk. Shift it 300 miles to the east and you might need the shovels in a hurry.
C.)December should end up being colder than you might like. Yes, there will be some mild days, but the main flow out of the northwest should keep us chilly. And there are some hints of a potential stormy period at the end of the month.
E.) January will start off cold but should turn much milder by comparison as the cold weather pattern collapses at least temporarily. If it collapses completely, we are talking a winter like 1989-1990. December was nasty and snowy, and then winter was over.
F.) February is the tricky one. I expect that after the January break, the cold will reload and might reload with a vengeance. This is the weakest part of the forecast.
G.) Overall I expect the winter to average about .25° degrees below normal. On the good side, prices for natural gas and home heating oil continue to be very reasonable.
H.) As for snowfall, look for 11.2” of snow, that is at or just slightly above normal for the year. I do not look for a “blockbuster” storm this year (that happens this forecast is in the trashcan), but one “good” one and a few “minor” storms.
I.) With that late December potential for something, I give us an 18% chance of seeing a White Christmas. Better than average, but much lower than the chances of getting coal in my stocking on Christmas morning.
Enjoy, and let’s see what happens.