Eastern U.S. on alert for thumping from another major winter storm

AccuWeather forecasters are putting a large segment of the eastern United States on notice for another major winter storm expected to hit in the days ahead.

The wintry weather will be the result of a disruptive storm that will bury the Heartland under heavy snow then unleash substantial snow and ice across parts of the Southeast, before taking an unusual route to the north from Sunday into Monday.

As it makes the trek north, it will trigger heavy snow, ice and rain throughout the mid-Atlantic, central Appalachians and New England.

The path the storm is predicted to take is extremely rare in that it will dive well to the south and southeast across the Central states before making a sharp turn to the north and northeast along the Atlantic Seaboard, according to AccuWeather meteorologists.

Atmospheric conditions, including the position of the jet stream and different pieces of energy, will come together in such a way that it is likely to do just that.

On top of that, the storm is likely to strengthen rapidly as it moves along. It could intensify quickly enough to become what meteorologists refer to as a bomb cyclone, which could enhance impacts as it pounds the Northeast.

A bomb cyclone is a storm that strengthens so fast that the barometric pressure at the storm's center plummets by 0.71 of an inch of mercury (24 mb) or more in 24 hours.

A storm that rapidly intensifies in this manner is able to grab copious amounts of moisture due to strengthening winds and, in turn, can unload heavy precipitation.

The conditions ahead of the storm will be primed for winter weather mayhem.

"A separate storm over the North Atlantic at the end of this week will create a wedge of cold air in the Northeast and at the same time will prevent the next major storm from escaping out to sea during Sunday and Monday," AccuWeather senior meteorologist Joe Lundberg said.

The winter storm still is days away from impacting the eastern United States, and because of that, meteorologists are still analyzing the precise track the storm is bound to take.

As of midweek, some of the energy that will factor into the Sunday-to-Monday storm in the East was still out over the northern Pacific.

AccuWeather forecasters are examining different possibilities for the future track of the storm, and the scenarios range from a storm that hugs the East Coast to a storm that will track inland of the coast.

In either case, and even though the storm's strength is not expected to reach the magnitude of the Blizzard of '93 or the Blizzard of '96, the storm from Sunday to Monday has the potential to pack a punch with a period of heavy snow on its cold northwestern flank and heavy rain or heavy snow changing to rain on its warmer southeastern side.

The Blizzard of '93 brought significant snow to Atlanta, as this storm may do, and went on to bring both heavy rain and heavy snow to New York City and Washington, D.C. Both forms of precipitation are possibilities in these metro areas with the upcoming storm.

"Enough cold air is likely to be in place for an all or mostly snow event from near and west of Interstate 81 corridor in the Northeast states, while near and south and east of I-95, rain is likely to be the primary form of precipitation," AccuWeather senior meteorologist Bill Deger said, adding that in between snow, ice and rain may fall.

In portions of the central Appalachians during the height of the storm and at the onset of the storm close to the Atlantic coast, snow may fall at a furious pace of 1 to 3 inches per hour.

A snowfall rate of this intensity can quickly bury roads and overwhelm road crews, especially along roadways that experience a heavy volume of traffic.

Snow is likely to fall throughout the duration of the storm in parts of the Appalachians, and a foot of more of snow could pile up. Conditions will deteriorate quickly in the all-snow zone as increasing winds will lead to significant blowing and drifting of snow.

Even in some areas where rain is likely to take over at the height of the storm along Interstate 95 in the mid-Atlantic and part of New England, a few inches of snow can fall beforehand. The speed of the change to rain or even a wintry mix, including ice, will determine snow accumulations.

However, AccuWeather forecasters noted that a shift in the storm's track by as little as 50 miles will affect the outcome.

"Should the storm manage to drift 50 miles or so off the coast while heading northward, I-95 cities from Washington, D.C., to Philadelphia, New York City and Boston could be buried in snow with little or no rain and ice mixing in," Deger said.

In that case, a true nor'easter would unfold, and even blizzard conditions might develop along the I-95 corridor.

If the storm takes a path farther to the west, right along or even west of I-95, the heaviest snow will instead fall along the western slopes of the Appalachians to portions of the Ohio Valley and part of the Great Lakes region.

A rainstorm would unfold along the I-95 corridor. In between, a wintry mix could create slippery travel along the I-81 corridor, according to Deger. In that scenario, the worst of the storm would avoid the major travel hubs up and down the Eastern Seaboard, but some delays still would be possible.

As the storm moves north-northeastward along the Atlantic coast, other hazards are likely to unfold. Increasing winds from the strengthening system will lead to a period of coastal flooding and beach erosion.

On the southeastern edge of the storm, thunderstorms may become strong enough to bring the risk of severe weather. That could occur from Florida to the coastal Carolinas and perhaps Long Island, N.Y., and eastern New England.

Major disruptions to travel, shipping, supply chain and COVID-19 testing are anticipated due to areas of rapid snow accumulation, icy conditions and even flooding rain. The storm has the potential to strand travelers on the highways and at airports as people move about for the long weekend.