The Mall in downtown Washington is covered with snow Sunday. (Carlos Barria/Reuters)

There are rumors of a winter storm over the weekend. Rumors you may have even been tipped to right here at the Capital Weather Gang. While the large-scale atmospheric pattern does favor another storm, the kind of weather it might bring (rain? snow? something in between?) is still a mystery. That being said, it’s something we will be watching closely, because there will be plenty of cold areas for this storm to draw from, should it form and follow a track that would affect Washington.

In short, we are very confident that there will be a storm over the weekend. But we have little confidence in the all-important details that determine our impact. The European model shown below displays how much uncertainty there is about the storm track. This image shows 50 different forecast model opinions on where the storm center could be Sunday morning.


This image shows 50 forecast model opinions (ECMWF) on where the storm center could be Sunday morning. It encapsulates the uncertainty of the weekend storm very well.

Note that a number of lows track north of Washington — that would mean rain or a wintry mix here. Others have the low in North Carolina or off the coast. Those tracks would argue for snow. Others offer still a third possibility of having more than one low along the front. The first one tracks far enough west to pump in enough warm air to give us rain but then pulls in cold air. The next frontal wave produces rain transitioning to snow before ending. There is a high level of uncertainty.

The Canadian forecast model and experimental GFS-FV3 serve up a “cutter” storm that tracks well to our west, putting Washington on the warm side of the storm — that would mean rain. In contrast, the operational GFS displays a more complicated scenario that would deliver rain and a wintry mix, then a period of light snow with rapidly falling temperatures.


Monday’s European model also tracks the initial storm far enough west to put us in a southerly flow ahead of the storm. This argues for mostly rain. But like the GFS, the European model has a strung-out look to the low that might offer a period of light snow as temperatures crash behind the front ushering in bitter cold.

The picture on winter storms is always fuzzy seven days in advance. As of Monday, rain or a wintry mix looks more possible than all snow. However, the models have been bouncing around on how the weekend’s storm might affect the area, and it’s too early to rule out anything.

All we can say for sure is there will be a winter storm somewhere on the East Cost over the weekend, and we’ll be tracking it through the week.

Read more:

Forecast review: It was hard to keep up with ‘Snurlough’

Reader photos of ‘Snurlough’: It was big and you loved it

How the weekend winter storm happened, meteorologically