WASHINGTON - The coldest air of the winter season so far is just days away from arriving across the Washington, DC region, with the threat of snow trailing not too far behind. Looks like Punxsutawney Phil has some explaining to do!
So what can you expect from the approaching storm? Here are five things you need to know for this one:
1. Rain, snow, ice... or the trifecta?
The biggest question of the coming storm is what type of precipitation will it be, and could there possibly be a change at some point? The air mass that will be over DC this weekend will be Arctic in nature, and many locations will wake up in the single digits on Sunday morning. This cold air mass will begin exiting the region as the storm approaches.
At this time, models show considerable agreement that this event begins as all snow for the region. The question becomes-- do we start to mix in enough air at some point to change to sleet, freezing rain, or all rain? That is a question for which we need more time and more data before we can answer reliably.
2. Timing: A four-day weekend on the way?
While models may not all agree on the type of precipitation, they are in relatively good agreement on the timing at this point. For our friends in West Virginia and the Maryland Panhandle, this event may start as early as Monday morning as light snow, with the threat for light snow increasing in DC as we head into the late afternoon and evening hours of Monday.
Without question, what falls will stick immediately. The frigid weekend we are about to endure ensures that. Road conditions, even main thoroughfares, will likely be very messy Monday night. From that point forward, precipitation type will determine whether or not travel conditions improve, or get worse by Tuesday afternoon and evening.
Is the potential there for closings on Tuesday? Absolutely. Are they guaranteed? Absolutely not. Unlike the January blizzard where they was widespread agreement on massive snow for everyone, we have a lot more disagreement this time around. As a result, it will take several more days before we start to develop a clearer picture.
3. Snow totals? Don’t even ask.
Everyone wants to know how much they could get. At this point, it would be downright irresponsible to give totals. There is not one model that has been consistent with this system, and due to the likely development of what is known as a wedge (cold air trapped against the mountains at the surface) which all models handle extremely poorly, we need to be especially cautious here.
We do not anticipate making a “first call” map until models show more consistency. As it stands at this moment, the odds for more snow increase as you head north & west towards the mountains and decrease as you head east & south of I-95. The brutal truth is that I do not care what your weather app says for snow totals. At this point, it is probably wrong.
4. Once again, this is not #TheWinterAwakens.
The storm that we had in January was incredible both in how models handled it, and how many things came together perfectly to create such widespread, heavy snowfall. These storms are the exception rather than the rule, otherwise our jobs as meteorologist would be much easier.
The only thing that the coming storm has in common with the January blizzard is that it is a southern tier storm, meaning it will track across the southern United States and grab gulf moisture before heading in our direction. This will allow the storm to have better structure than say the Tuesday’s event here in the District, which struggled with moisture supplies as it tracked across the northern United States away from any significant body of warm water.
The coming storm is one that will make snow lovers happy in one area and very disappointed in another, but at this time we are unsure of where that will be.
5. Winter Break is coming... but it's not over yet.
Following the storm there is widespread agreement on a break from the winter pattern heading into late next week and the week beyond. Temperatures will return to the 50s and can’t even rule out a 60° day or two sneaking in at some point.
However, longer models are already hinting at the return of cold air as we head into the early March time period. Anytime we get cold at this time of year, we have to be on guard for the potential of more winter weather. If you recall, last winter the largest snowfall recorded in the District came in March (4.8” on March 5th, and Dulles received 9.5”).
After we get through the first half of March, we believe we will be able to close the book on the winter of 2015-2016.