Northeast to face wide range of impacts from next potent winter storm

A storm trekking across the country toward the Northeast will arrive this weekend, but the latest forecast indicates a shift in the amount of snow it will produce -- and where the snow will fall.

Even though the storm slated for the Northeast continues to trend warmer, snow is still forecast to bury the northern tier and blanket parts of the central Appalachians, while pockets of ice can pose a travel risk. Heavy rain may cause urban flooding near the coast.

A storm from the Midwest will strengthen and track far enough to the north to have a significant influence on the primary form of precipitation in the Northeast.

Since the storm in the Midwest matured very early on, it will have time to pull warm air in at many levels of the atmosphere in the Northeast this weekend.

The primary form of precipitation will be rain in Virginia, West Virginia, Maryland, Pennsylvania, Delaware, New Jersey, central and southeastern New York state and central and southeastern New England.

Despite the primary form of precipitation being rain in these areas 100 miles inland of the coast, a cold ground can cause a layer of black ice to form. In this situation, the black ice would be more common in areas that are shaded from the sun, such as the north side of buildings, gaps in the mountains and wooded locations.

Because of the patchy nature of the ice, some motorists and pedestrians may think the entire stretch of roads or sidewalks are just wet. The ground can be icy even though car or home thermometers show temperatures above freezing.

Adding to the spotty black ice risk will be the potential for locally dense fog.

There will be areas in the Northeast where shoveling and plowing operations are needed.

Locations where enough snow is likely to fall and accumulate with the storm will extend from the mountains of northern West Virginia and western Pennsylvania to western and northern New York state and northwestern New England.

From 6-10 inches (15-25 centimeters) of snow is forecast in parts of southeastern Ontario and southwestern Quebec. In this swath an AccuWeather Local StormMax™ of 14 inches (36 centimeters) are anticipated.

Areas from western to northern New York state, northeastern Vermont, northern New Hampshire and northwestern Maine can expect a 3- to 6- inch snowfall. A total of 1 to 3 inches of snow is forecast from the northern West Virginia mountains to the mountains of western Pennsylvania, the southern tier of New York state and in a narrow zone across central New England.

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The combination of heavy rain and gusty winds for a time can lead to travel delays in the I-95 corridor. Enough rain can fall along the coast to cause urban flooding.

Much of the rain may focus in a 50- to 100-mile-wide band that pivots northeastward across the Piedmont and coastal areas. Rain can be intense in this band with thunder, lightning and gusty winds.

This intense band of rain is likely to swing through Washington, D.C., Baltimore and Harrisburg and State College, Pennsylvania, during Saturday morning. Philadelphia and Dover, Delaware, are likely to be hit during the middle part of the day Saturday. The intense rain is then scheduled to hit New York City late Saturday afternoon and evening with Boston likely to be hit later Saturday night.

As the center of the storm from the Midwest moves in, colder air will rotate eastward from later Saturday to Sunday.

Enough moisture will accompany the cold air to produce snow showers from the Appalachians on north and west later Saturday to Sunday. However, it is unlikely for the snow showers to survive the trip to the coast. A swath of dry air, known as a dry slot will be prevalent along the Eastern Seaboard.

Temperatures are forecast to climb into the 40s in Boston, New York City and Philadelphia and near 50 in Washington, D.C., on Sunday. As a result, rain will subside and dry air will sweep in across the swath from much of Virginia to southeastern New England.

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