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Major winter storm, possible blizzard to slam New England Saturday

Heavy snow, strong winds and coastal flooding are possible, with the most severe conditions in eastern areas

Average snow projected through Sunday afternoon from dozens of simulations making up the European and American modeling systems. (WeatherBell)
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This article, first published Wednesday morning, was updated in the evening to note some models had reduced snowfall totals west and south of eastern New England. We also scaled back snowfall probabilities some in the city-by-city forecasts.

A major winter storm is set to slam parts of the Northeast on Saturday, with heavy snowfall, strong to damaging winds and coastal flooding all possible. The risk of a serious storm and possible blizzard conditions is highest in eastern New England along and east of the Interstate 95 corridor, including cities such as Providence, Boston and Portland.

A similar story could unfold in New York, but uncertainty remains sky-high in the Big Apple. Computer model simulations drop anywhere between an inch and a foot of snow in New York, making the forecast a nail-biter. Lesser snowfall is expected in Philadelphia and Washington.

The storm hasn’t even formed yet, and won’t until Friday, but its rate of rapid strengthening will easily qualify it as a “bomb cyclone.”

That said, meteorologists are still working to iron out the details of the storm’s ultimate track, which will have a bearing on snowfall totals and how far inland accumulations will extend.

“I know you’ve heard it repeated to death, but the key message continues to be the same: guidance is trending favorably for a big storm, but the exact track remains uncertain,” the National Weather Service in Boston wrote in an online forecast discussion Wednesday.

Some forecast models on Wednesday afternoon suggested the risk of a serious storm had decreased south and west of eastern New England and that mainly extreme eastern Massachusetts and downeast Maine would get walloped.

The setup

A pair of high-altitude weather disturbances, the key catalysts for the upcoming storm, were present on weather maps on Wednesday morning — one was moving ashore over the Pacific Northwest and the other was centered over the Alaskan mainland. Both will dive southeast over the Lower 48 during the back half of the workweek, overlapping and “phasing” over the Ohio Valley on Friday.

We’ll have a better idea of what will transpire with the nascent winter storm Thursday. That’s the first time that National Weather Service offices in Washington state and Oregon will be able to launch weather balloons into one of the instigating disturbances; that, in turn, should improve computer modeling.

Some snow probable in D.C. area Friday afternoon and night

As the high-altitude systems combine Friday, they will work to spin up a zone of low pressure off the Carolinas that will rapidly intensify as it moves northeast. Its abrupt drop in minimum central air pressure could classify it as a meteorological “bomb.” That bolsters the odds of heavy snow and strong winds.

There’s an outside shot that, through tapping into energy contained in the anomalously mild waters of the north Atlantic, the storm could double the pace of strengthening needed for “bombogenesis.”

Gulf of Maine waters spiked to record warm levels in fall 2021

A solid storm, and perhaps a blockbuster, in New England

At present, forecasters are still not sure just how close to the coast the storm will pass at it slips by Saturday. It could trek near the famed “benchmark” at 40 degrees north, 70 degrees west. That represents the textbook track for a high-end storm.

The American (GFS) model seeks to allow the storm farther out to sea, which would cut back on snow totals west of Interstate 95. Eastern Massachusetts, Downeast Maine, the New Hampshire Seacoast and Rhode Island could still be talking double-digit snow totals in that scenario.

Two-inch-per-hour snowfall rates are possible during the daylight hours on Saturday across Plymouth and Bristol counties, as well as the Cape and the Islands, in Massachusetts. Boston could see the heavy snow, too, along with possible thundersnow. Strong winds will probably gust over 60 mph across the Cape, too, with 45-mph gusts along the eastern Massachusetts shoreline. That may result in blizzard conditions with visibility below a quarter-mile.

Scattered power outages will be possible because of the high winds, especially from eastern Long Island to coastal Massachusetts.

Astronomically high tides, combined with a potential three-foot storm surge, also will result in coastal erosion and flooding.

Major uncertainty New York to D.C.

New York could see anything between very little snow and a foot. Forecasters won’t be able to offer much clarity until perhaps Thursday. It’s simply not known how far the western flank of the snow will extend. These uncertainties also extend to the south, where the Delmarva Peninsula and much of New Jersey could see anything between a modest and major snowstorm depending on the storm track.

For D.C., Baltimore and Philadelphia, the storm probably gets going too late to drop more than a couple inches of snow, but areas just to the east have a chance to see more substantial amounts.

City-by-city forecasts

Washington and Baltimore

Light snow will probably fall Friday afternoon and evening, perhaps briefly becoming moderate around or just after sunset. It may taper off quickly but linger southeast of the metro corridor into early Saturday. The snow should increase in both coverage and intensity over the Delmarva Peninsula.

Chance of at least 1 inch: 40-50 percent | Chance of at least 3 inches: 10-20 percent | Chance of at least 6 inches: 5 percent.

Philadelphia

Light snow will commence Friday night, but whether more significant snow develops will depend on the storm track. Winds will be breezy, with gusts nearing 30 mph during the morning hours Saturday. Snow should taper off around lunchtime Saturday.

Chance of at least 1 inch: 50 percent to 60 percent | Chance of at least 3 inches: 20-30 percent | Chance of at least 6 inches: 10 percent.

New York

It’s a nail-biter in the Big Apple — no two ways about it. Snow will sneak in during the predawn hours Saturday, falling steadily. The snow will become fluffier during the afternoon and evening hours as colder air filters into the region. It’s unclear how far west the system nudges, and, therefore, if the city gets into bands of moderate to heavy snow closer to the storm’s offshore center.

Chance of at least 1 inch: 70 percent | Chance of at least 3 inches: 45 percent | Chance of at least 6 inches: 30 percent | Chance of at least 12 inches: 15 percent.

Providence-Boston-Portland

A major winter storm is likely, and, if the European model is correct, a blockbuster is in the offing. Snow will fall during most of Saturday, beginning around or before sunrise and lasting through midnight. In southeastern areas, like inside of Interstate 495 in Massachusetts, will see a heavy, wet snow at first, while the New Hampshire Seacoast and coastal Maine should see lighter snow and temperatures in the teens. Blizzard conditions are possible.

Chance of at least 1 inch: 90 percent | Chance of at least 3 inches: 75 percent | Chance of at least 6 inches: 60 percent | Chance of at least 12 inches: Around 45 percent | Chance of at least 18 inches: 10 percent.

Interior New England

Snowfall amounts will walk a steep gradient from east to west. Beyond the Worcester Hills, there won’t be as much to measure, particularly west of Interstate 84. Northern Vermont and New Hampshire and western Maine will see the lowest amounts and perhaps no accumulation. But plowable amounts become pretty likely east of the central portions of Connecticut, Massachusetts and Maine.

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