Washington, D.C. snow forecast scaled back Wednesday night to Friday

This light mix of precipitation may continue intermittently for the next few hours, but shouldn’t amount to much. Not until later this evening, after 7 or 8 p.m., do we expect steadier, more significant precipitation to develop, which could start to accumulate, mainly in northern Maryland. See our storm timeline for more information below.

Original article from early afternoon

The two-part winter storm which appeared like it might blanket the immediate D.C. area in several inches of snow might not produce much at all, based on the latest projections. In fact, only modest amounts of snow may fall, if that.

However, some accumulating snow is still possible Wednesday night, especially north of the Beltway. Another round is possible Thursday night, especially south of the Beltway. In other words, Washingtonians caught in the middle may not see much snow accumulation.

For snow lovers in the immediate D.C. area, this is the worst possible scenario: two wintry waves moving through, but the first missing to the north and the second scooting to the south. But for those needing to travel Thursday and Friday, the decreased snow potential is surely welcome news.

While perhaps not producing a ton of snow, the weather pattern will remain very active through the weekend, when another winter weather event may deliver a dose of snow, sleet and freezing rain Saturday and Saturday night.

How much snow is reasonable to expect?

• For the first wave, late Wednesday into Thursday morning (forecast amounts at the top of this article): In the immediate area, just a coating to a couple inches is possible, mostly on the grass. North of the Beltway, 1 to 3 inches is possible, with up to 2 to 4 inches in northern Maryland. Relatively mild temperatures, staying above freezing, are the major limiting factor for snow Wednesday night, especially from the District south.
• For the second wave, Thursday night into Friday morning (forecast amounts shown below): In the immediate area: a coating to a couple inches is possible. One to three inches could fall toward central Virginia. With the arrival of colder temperatures, dropping below freezing, snow will have improved chances of sticking late at night.

Small changes in the forecast track of the two waves could still yield more or less snow than currently predicted.

Here’s how we see the two waves of precipitation evolving. Note that, for the given temperature ranges, the lowest temperatures will occur north and northwest of the District, with the mild temperatures around the District and to the south and southeast.

4 to 7 p.m. Wednesday: Patchy light snow or rain-snow mix develops. No accumulation. Temperatures 35 to 40.

7 p.m. Wednesday to 1 a.m. Thursday: Snow, possibly mixed with sleet north of the Beltway. Light accumulation possible. From the Beltway south, a mix of snow, sleet and rain. No accumulation expected. Temperatures 32 to 36 degrees.

1 a.m. to 7 a.m. Thursday: Intermittent snow, possibly mixed with sleet north of the Beltway. Accumulation likely and slick roads possible. From the Beltway south, a mix of snow, sleet and rain, possibly changing to snow toward dawn. Light accumulation possible, mainly on the grass. Temperatures 31 to 35 degrees.

7 a.m. to 10 a.m. Thursday: Snow and wintry mix exits west to east. Temperatures 32 to 35 degrees.

10 a.m. to 7 p.m. Thursday: Pause in precipitation, mostly cloudy skies. High temperatures 33 to 37 degrees.

7 to 11 p.m. Thursday: Chance of snow developing, especially south of Beltway. Temperatures: 28 to 33.

11 p.m. Thursday to 7 a.m. Friday: Light snow at times, especially south of Beltway. Light accumulation possible with slick roads. Temperatures 25 to 30.

7 a.m. to 10 a.m. Friday: Snow exits to the east. Temperatures: 26 to 31.

On our winter storm impact scale, the first wave of this storm rates as a Category 1 “nuisance” event in suburbs north of the Beltway. Enough snow and/or sleet may fall Wednesday night into Thursday morning for slick untreated roads and sidewalks which could lead to delays Thursday. But we do not expect widespread, major disruptions.

(We’ll assign a rating for the second wave, if needed, Thursday.)

• An Arctic front will be to our south, providing a supply of cold air at low and mid-levels. Aloft, winds blowing from southwest to northeast will blow over the top of the cold dome, generating two waves of wintry weather between late Wednesday afternoon and Friday morning.
• There will likely be a mix of precipitation types Wednesday night into Thursday morning, especially from the Beltway south as low-level temperatures struggle to fall below freezing and the southwesterly winds aloft warm the mid-levels enough to possibly change the snow to rain or sleet. Areas north of the Beltway have the best chance of seeing all or mostly snow and some accumulations are likely.
• The heaviest precipitation Thursday night into Friday morning with the second wave is likely to be south of the city. Some models keep all the snow associated with the second wave south of the city.

• How much mild surface temperatures and mixed precipitation will hold down snowfall totals Wednesday night into Thursday morning.
• How far north will mid-level warming will push the mixed precipitation and rain north Wednesday night. Will it reach north of the city or stay just to the south?
• How far north will the snow extend Thursday night into Friday morning. Will its northern extent overlap where snow fell Wednesday night and Thursday morning? The models have been trending lighter and farther south with the Thursday night snow. Will it stay to our south? Without it, the Beltway and points just to the south may not get any accumulating snow through Friday.

If two possible doses of wintry weather through Friday aren’t enough for you, Saturday presents another opportunity. As Arctic high pressure continues feeding cold air into the region at low levels, another wave of overrunning precipitation is likely to move through.

The combination promises to bring perhaps a little snow along with the dreaded mix of sleet and freezing rain. The big question mark Saturday is whether any snow falls before the icy precipitation takes over and then whether more sleet or freezing rain falls. Right now, models suggest perhaps a coating of snow before a switch to sleet around the D.C. area with more of a freezing rain threat to the southwest.

It appears overall precipitation amounts will be light, but it doesn’t take much ice to cause problems given predicted temperatures from 25 to 30.

This third wave does look to exit Saturday night leaving behind dry conditions Sunday. Another messy winter storm could approach Monday night and Tuesday. We’ll provide more information on these latter two events in the coming days.