Snow or just cold rain? What forecasters say D.C. should expect this weekend

Forecasters are sounding a cautious alarm about a coastal storm expected to develop late this weekend, warning that the Washington region is perched on a sharp rain-snow line that could mean anything from a chilly, mostly wet Sunday to several inches of heavy, wet snow in parts of the metro area.

As of Thursday afternoon, computer models showed a strong storm likely to form off the Mid-Atlantic coast Sunday into Monday, with the exact track and timing of cold air still uncertain, according to the National Weather Service. That combination has left local and national forecasters stressing the storm’s potential, along with its potential to disappoint snow lovers.

“A high energy but low predictability pattern looms for late this weekend,” the Weather Service office in Sterling, Virginia, said in a forecast discussion. The discussion notes that at least some snow now appears likely somewhere in the region late Sunday into Sunday night, with possible outcomes ranging from light to significantly higher amounts.

Track, Track, Track

The biggest question is the path of the coastal low.

If the storm hugs the shoreline, it would be more likely to throw a shield of heavier precipitation, including accumulating snow, back toward the Interstate 95 corridor. A track farther offshore would keep the Washington area on the fringe, with lighter precipitation and a better chance that rain dominates, especially in and south of the District, forecasters say.

Local television meteorologists have been stressing that knife-edge risk. In a forecast update Thursday morning, WTTG-TV meteorologists Tucker Barnes and Cesar Cornejo said the region already has cold air in place and is now waiting on the track of the developing coastal low to determine whether the D.C. metro ends up seeing snow or a cold rain. Current model runs keep the storm just offshore, they say, but only a modest wobble inland could shift the balance toward a more significant winter event.

Similarly the NWS Weather Prediction Center in College Park shows the developing coastal system with elevated probabilities for significant snow from the Mid-Atlantic into New England, with higher odds if the low tracks close to the coast and more limited impacts if it slides farther offshore.

Marginal Temperatures, Messy Precipitation

Even if the storm comes close, temperatures may make the difference between a slushy mess and a more impactful snowfall.

The NWS expects cold air to filter into the region as the storm arrives rather than being firmly in place ahead of time, with highs Sunday near the upper 30s to around 40 and temperatures falling toward freezing Sunday night. That profile favors rain or a rain-snow mix during daylight hours, then a better chance for snow to stick after dark, particularly on grassy and elevated surfaces.

The Capital Weather Gang laid out the picture in a Thursday afternoon post on X, saying forecasters are leaning toward a relatively minor snow accumulation mainly on Sunday night, though with the caveat that some modeling still suggests more substantial totals are possible. In the more likely scenario — in which two atmospheric disturbances fail to merge — the gang put the chance of at least 1 inch of snow at 40 percent, at least 3 inches at 25 percent, at least 6 inches at 15 percent, and a foot or more at just 5 percent. If the two disturbances do merge, the gang noted, the ceiling for accumulation would go up considerably.

One outlier model, the American GFS, simulated three feet of snow in Washington on Thursday morning, but the Capital Weather Gang called it an extreme outlier with a bad track record this winter.

Baltimore-based meteorologist Justin Berk, who runs JustinWeather.com, has framed the setup as notably more favorable for points north of the District. In a Thursday morning blog post, he highlighted high odds for at least 1 inch of snow and a meaningful chance for 3 inches or more around Baltimore, based on multiple model suites, pointing to the sharper cold and slightly better storm positioning farther up Interstate 95.

Data-driven national outlooks tell a similar story. The Weather Channel’s 10-day forecast for Washington shows highs near the upper 30s and lows around 30 on Sunday with precipitation chances above 80%, suggesting a raw day with mixed precipitation.

A Narrow Band of Higher Risk

While no major outlet is publishing firm accumulation maps yet, a common pattern has emerged: the farther north and west from downtown Washington, the higher the snow risk.

The NWS notes that all major ensemble systems now show at least some snow somewhere in its forecast area Sunday into Sunday night, with amounts highly dependent on the exact track and intensity of the coastal low.

The Capital Weather Gang’s Thursday timeline breaks the event into three phases: a Sunday morning into afternoon period of light rain or rain-snow mix, with temperatures probably in the mid-30s or higher making accumulation unlikely except perhaps on grass; a Sunday evening and overnight window when a disturbance sweeping in from the north could bring accumulating snow as temperatures drop into the low 30s, with areas north and west of downtown D.C. having the highest chance of at least an inch; and a Monday taper, with any snow ending during the morning hours as afternoon highs climb back toward 40.

Mr. Berk’s probability charts on zero in on Baltimore, but they effectively place central Maryland in a favored zone if the storm comes close, pointing to a sharp gradient across the metro region. Storm Team 4 at WRC-TV has suggested that 1 to 3 inches of snow are most plausible north of the Interstate 66 and U.S. Route 50 corridors under current projections, with lower amounts or mainly rain to the south.

In broad terms, the highest accumulation risk sits north and northwest of the District, toward Frederick, central Maryland and the northern suburbs. Inside and just around the Capital Beltway, outcomes range from little more than slush to several inches in a favorable scenario. Southern and southeastern suburbs lean more toward a chilly rain unless the storm shifts inland.

Forecasters also caution that the late February sun angle and relatively warm ground will work against daytime accumulation on paved surfaces, particularly in the city, further focusing the concern on Sunday night.

Two Storms, One Weekend

This weekend’s potential winter weather comes on the heels of a separate, all-rain system moving through the area Thursday into Friday. The National Weather Service expects periods of rain and drizzle to linger into Friday as a front stalls near the region, followed by a drier and more seasonable Saturday with highs in the 50s. That lull sets the stage for the more volatile coastal storm threat on Sunday.

Local television outlets and the Weather Prediction Center outline a similar timeline: wet weather to end the workweek, a breather Saturday, then a colder, stormy Sunday with the precise rain-snow mix highly dependent on the storm’s track and the arrival of colder air.

’Credible Threat, Not a Lock’

For now, meteorologists are trying to thread the needle between alerting the public and overhyping a storm that could still slide offshore.

Forecasters across the board have all stressed that outcomes remain wide open, from a near-miss that brings mostly clouds and gusty winds to a more substantial late-season snow for parts of the metro area. Many have deliberately avoided specific snowfall numbers, leaning on probabilities and ranges until models converge.

The consistent advice: plan on a raw, unsettled Sunday, be prepared for wintry travel Sunday night, especially north and west of the District, and check forecasts frequently as new data comes in.

Looking to Friday

Greater clarity is expected to emerge Friday as the upper-level disturbances responsible for the storm move over land and into the network of weather balloons and surface observations that feed computer models, the Weather Service says.

Residents and commuters should watch for winter storm watches or advisories from the National Weather Service, particularly for northern and western suburbs, along with updated snowfall probability graphics from the Weather Prediction Center that could better define the line between mostly rain and meaningful snow.

Until then, the Washington region remains, as it so often does in winter, right on the edge.