It seems to be the question on everyone's mind, where the heck is the snow?
As of January 28th, cumulative snow total at all three of the area's major airports (where official records are kept) have yet to reach the 1" mark. Aside from one near miss in early January that brought portions of Southern Maryland more than half a foot of snow, the season has been filled with a lot of disappointment for the snow lovers around our region so far.
So what's up? Well, the temperatures, that's what. December came in generally as expected with our winter outlook. Two strong shots of Arctic cold, but not a lot of snow. Our expectation was that the pattern would continue into January, which is typically a month where we see more clippers begin to make their way southward out of Canada.
That could not have been farther from what happened.
A strong ridge developed over the southeast United States, which is a strong warm signal for our neck of the woods. This feature forced the storm tracks inland up through the Great Lakes, which is a track that favors rain over snow in the Mid-Atlantic region. Such a track also enhances the warmth in the region.
How warm? Given the forecast for the next three days Washington, DC is currently on pace to be tied with 1974, 1950, and 1949 for the fourth fewest January days below freezing on record with only nine, in a month that usually averages twenty-two. As of this morning, this January has been the twelfth warmest on record.
How bad is the drought?
But how bad of a snow drought are we really in? Well consider chart two above, which group's snowfall recorded through the first three months of the snowfall season (November-January) over the last 25 years.
Only one year had less snow though this point in the season than we do now, the super warm winter of 1997-1998, nineteen years ago. Washington, D.C. is currently in its worst snowfall drought since the turn of the millennium. But the question is, does the lack of snowfall through what is typically the coldest month of winter mean that we are doomed to a lack of snow heading into the second half of the snow season? Well it is hard to say.
Forecasting the weather in the long range is like forecasting who is going to win the super bowl. Sure, you know who is showing up to play in the game, but you do not know exactly how the game will unfold. By the end of the game, things might turn out exactly like you expect, but throw in a surprise play or two and a total upset can easily happen. Generally speaking when we look at something like snowfall, it comes down to statistics.
Should snow-lovers have any hope?
Let us look at past winters where snowfall came in well below normal though the month of January. There are only 10 other winters in the entire weather history of DC (which stretches back to the late 1800s) that have seen half an inch of snow or less though this point in the season. 90% of those years had more snow during the February - April time period, with 50% of those cases receiving over half a foot of snow before the season was over.
This sample size is a little small for my liking, so let us expand to include all years where Washington received less than 3" of snow through this point in the season, considerably less than the 8.4" that is the average over that same time period. This expands our data set to 30 years, which is shown in chart three above.
In these cases, a whopping 26 of the 30 years (86.7%) saw more snow during the second half of the season. Once again, half of these cases (15) saw snow total exceed half a foot during the February to April time frame. The similar numbers seen between the small sample size of 10 and the larger one of 30 should give snow lovers a good amount of hope that we probably have not seen the last of winter just yet.
What influences our weather?
Still, we wanted to take the data and push it just a little bit farther. While there are many different factors and phenomenon around the globe that influence our weather here in the United States, one of the most important (and most commonly known) is El Niño and La Niña.
The majority of major snow events in this region have come during El Niño winters, take last year as an example. Currently this winter we have been in a neutral to weak La Niña pattern, which is one of the reasons we did not favor a major snow event when we wrote our winter outlook back in October.
So we took our grouping of 30 years and looked at only those years which were also in this neutral to weak La Niña leaning pattern. We once again got a grouping of only 10 years (shown above) with the stats slightly different from the larger group of 30 we previously looked at. Only 80% of cases went on to see more snow in the second half of the season than during the first half, with only 40% of these receiving more than a half a foot of snow, which last happened during the winter of 1992-1993. What is interesting about that year is that the majority of snow fell in mid-March during what is now famously known as the Storm of the Century. Parts of the region received over a foot of snow with that storm.
The general take away is this, it is still far too early to write off this winter as over from a snow perspective despite the snow drought through the first half of the snow season.
Historically, February is actually the most active month when it comes to the bigger snow storms, followed by early March. This is particularly true in the types of years with the global weather pattern we are currently seeing (neutral/weak La Niña). That being said, we still do not favor getting any storm to the level seen last year (2-3 feet), but still anticipate a more active storm pattern as we head through the next couple of months.
Will the wintry weather return return this week?
So with February beginning this week, is there any sign of winter returning? In fact there is!
However, what impact they will actually have on our region remains to be seen. The first chance is actually Sunday night through Monday morning (shown above) when a weak piece of energy will slide out of the mountains and work its way across our region.
It is likely to bring some scattered, light snow showers along for the ride which could put down a spotty coating here or there around the region, with the exception of the mountains to the west which could pick up several inches. The only concern for this system will be if the snow is able to linger into the Monday morning rush it could lead to a few slick spots, however at this time we do not anticipate widespread issues with this storm.
When is our next risk for winter weather?
The next risk of snow comes right on Monday's heels by Tuesday evening.
Models currently show a clipper system rapidly moving across the Great Lakes and spilling into the Northeast. As things stand right now, this system is too far north to bring us any widespread snowfall activity on Tuesday other than a few flurries.
Clippers are notorious for how difficult they are to forecast however, and a small southward jog in the storm track could mean snow issues for our region potentially during the evening commute on Tuesday. Remember that evening commute with the clipper before the big blizzard last year? Yes we are trying to avoid that this year.
Again this one looks like it is currently missing our region to the north, but due to its close proximity we are watching it very closely.
Are you tracking any other winter weather?
The third risk for snow comes into the region on Friday as a wave of low pressure tries to organize itself along a stalled frontal boundary south of the DC region.
If it is able to get its act together enough, models currently indicate that we could have the potential for a little light snow during the morning commute on Friday. The problem is, the features necessary for this storm's formation are not all in place yet, and we do not believe we are getting a clear picture of what this system possibly could (or could not) be just yet.
Just know that the late workweek is another time period that we are watching closely, but as of this moment it is not something we are overly concerned with. Just another light snow threat.
What about next weekend?
The case is a little different when it comes to next weekend.
There is currently good agreement from multiple models on a storm somewhere in the eastern half of the county sometime between next Saturday night and next Monday night. Both the American and European models showed a significant snow event for the region next Monday last night, and my Facebook page subsequently lit up with questions.
There is a problem though, and that is that we are talking about a system that is more than a week away. While models can offer clues as to what the pattern may be like, they almost never get a storm track exactly right that far in the future. Take the image above, three successive runs of the exact same weather model (American). Friday night's snow-tastic model run is shown on the left.
By Saturday morning, the same model showed all rain (center image) with the storm tracking up the Appalachian Mountains instead of up the coastline. As of Saturday afternoon, the same model had shifted back to a snow event (right image) with the low back off the coast.
Which is right? Good question. Based on various other features I am currently leaning towards something "not all snow" but it is an extremely low confidence forecast because it is simply too early to tell. So long as next weekend's timing holds true, there will be at least 30 more runs of that model that need to be looked at over the next week before the storm hits, and I expect most of those runs to show something different from what they are currently showing.
Be careful what you see on social media over the next several days concerning next weekend, I think we need to get to at least Wednesday or Thursday before we can have any reasonable confidence on what this storm will end up doing.
Question or comments on this story? Looking for updates on the snow events? You can chat with me on Twitter and on Facebook. I'll be updating those pages with the latest information all week long (and beyond!).