A dark-eyed junco in a heavy flurry. (Erinn Shirley)

We’ve been seeing the hint of snow in the forecast next week for a few days now. On Tuesday and Wednesday, a low-pressure system will likely develop somewhere along the East Coast. Where, exactly, that happens will determine whether the D.C. region will get snow.

As always, there are some uncertainties.

If that storm develops to our south — say, just off the Carolinas’ coast — we will likely see snow. If it develops north of the District, we will either get rain or be entirely dry.

The last couple of model runs have trended toward the former scenario — that the low will form to the south, enhancing the chance of snow. However, even if that happens, snow is not a guarantee; it could actually end up being too far south and east to provide us with any precipitation.

Here’s a rundown of what the crystal-ball weather models are telling us today:


Snowfall potential as forecast by the European model on Friday morning. (stormvistawxmodels.com)

Last night and this morning, the European model suggested a Wednesday snowstorm with a strong upper-level trough and a surface low that develops just off the Carolina coast.

Today’s Global Forecast System model suggests a period of light snow Tuesday but puts the main storm too far east of the North Carolina coast to give us meaningful snow. However, the upper-level trough looks strong enough that it needs to be watched closely.


A deep upper-level trough is predicted by the European model to push down into the Southeast midweek. That would increase the chance of snow in the D.C. region.
(stormvistawxmodels.com)

The differences between the light dusting (or even no snow) GFS solution and the snowy European one is not that great. Both models have very similar upper-level patterns, with a strong, deep upper system approaching the coast Wednesday. The main difference is the GFS develops the low with the upper system a little later and farther off the coast than the European.

The European also has a much better defined coastal trough that would help spread the precipitation to the north. Subtle changes in the position of the low will markedly change the forecast. Right now, either solution is possible.

Just the fact that we’re expecting an East Coast low next week means the snow threat has increased. On top of that, we’re going to have an Arctic air mass in place — the one that’s arriving literally overnight and will push lows down into the teens this weekend.

This system has the most snowfall potential of any system so far this winter. However, it also has the potential to miss us if the low develops too far offshore or to our north. We’ll be monitoring the system.