A light blanket of snow fell in Ashburn early Friday. (Jahi Chikwendiu/The Washington Post)

If the slop early Friday wasn’t enough for you, the new month of March offers two more chances for a messy mix of rain and snow through its opening weekend. Then, a blast of cold arrives.

Friday night into Saturday morning: Wintry mix potential has increased, especially north

A slug of precipitation is expected to move into the region this evening (between 5 and 7 p.m.), and it may not just be liquid form. Especially from the Beltway and to the north and west, we may see a mix of rain, sleet and snow. The chance for frozen precipitation, freezing rain, sleet and snow increases the farther north and northwest you go.

“A possible winter weather threat has snuck up on us a bit for our colder areas,” said Wes Junker, Capital Weather Gang’s winter weather expert.

Within a one-county radius of the District, temperatures should mostly remain just above freezing, so accumulation — if any — should focus mostly on grassy areas. But, as close by as northern Montgomery County (Gaithersburg, Germantown, Damascus and Clarksburg) and Loudoun County, temperatures may be cold enough for slick spots on untreated paved surfaces.


NAM model shows snow and sleet in northern Montgomery and Loudoun counties and to the north and west at 10 p.m. Friday.

Winter weather advisories are in effect from 7 p.m. Friday to 7 a.m. Saturday for northern Maryland and western Virginia (near the Interstate 81 corridor) for a glaze of freezing rain. However, especially in northern Maryland and perhaps into the western half of Loudoun County, snow and sleet could enter the mix, as well, with the potential for an inch or two.


Forecast snowfall from National Weather Service through Saturday morning. (National Weather Service)

The main area of precipitation is expected to pass by 1 a.m., and conditions should improve thereafter. But pedestrians and drivers should use caution venturing out first thing Saturday.

Sunday and Sunday night: Mostly rain, but some mix in our colder areas

Another slug of precipitation is likely to move into the region around midday Sunday along an Arctic front entering the region. The question is how much cold air is in place when the precipitation arrives.

The European model says not enough for meaningful snow in most of our area, but the American model says not so fast. It is forecasting substantial snowfall, especially in our colder areas to the north and west of Washington.


American (GFS) model shows snow in the Washington region, especially west of Interstate 95, on Sunday evening.

We lean toward the rainier European model solution. It is the more accurate model in general, has been consistent in its forecasts (unlike the American model, which has jumped around), and our region is usually more rainy in these types of patterns during early March.

That said, it’s a close enough call that we would be foolish to rule out snow, especially in the colder parts of our region, as the storm track could change.

The European model does suggest precipitation could begin as a brief period of snow and sleet on Sunday afternoon, even in the immediate area, but temperatures should be above freezing. It then predicts mostly a rain event through Sunday evening until the precipitation tapers off after midnight Monday morning.


European model forecasts mostly rain in the Washington region Sunday evening but mixed precipitation and snow well to the northwest. (WeatherBell.com)

The European model does show mixed precipitation and snow for the duration of the event in northwest Virginia and west central and western Maryland (from around Winchester and Hagerstown westward). So these areas seem likely to deal with winter storm conditions. Areas from Frederick County (Md.) westward are under a winter storm watch Sunday.

Cold next week

Behind Sunday’s storm, very cold air will surge south into the region. Here are the forecast highs and lows next week from the American model. Remember that average highs are in the low 50s:


Ten-day temperature forecast from the American (GFS) model. (WeatherBell.com)

No real signs of any spring.

Quick review of Friday predawn snow

Our forecast for the snow that fell before most of us awoke this morning worked out pretty well.

We’re still wondering why Arlington County canceled school at 6 a.m. after the precipitation had ended, when snow mainly coated just the grass!