In a typical winter, residents of the Mid-Atlantic and Northeast might see one or two big storms, known in the region as nor’easters, because of the strong northeasterly winds that accompany them. This winter, however, is not ordinary.
The second in what may turn out to be a string of three back-to-back nor’easters is set to hit the Mid-Atlantic and Northeast starting late Tuesday night, and lasting into Wednesday night. Like the last storm that brought damaging winds, coastal flooding, and heavy rain and snow, this one will also have its array of hazards.
First, it has more cold air to work with, making snow the predominate precipitation type, especially along and just to the northwest of Interstate 95. Depending on the exact storm track, parts of eastern Pennsylvania, northern New Jersey, southern New York, much of Connecticut, and inland areas in Massachusetts could wind up with a foot or more of heavy, wet snow from this system.
High winds will again be a threat for coastal areas, though they’ll be much lighter when compared to the previous storm, which brought hurricane force winds to much of eastern Massachusetts. The storm could slow efforts to restore electricity to hard hit areas that lost power in the last storm.
The forecast details still need to be worked out, but even the big cities of Philadelphia, New York, Hartford, and Boston, are likely to see at least some accumulating snow from this storm — although a rain/snow mix is possible for a time.
Computer models had been showing this storm threat for about the past week, giving meteorologists higher than average confidence in calling for a significant event. Models are also hinting at a third storm to come late this weekend, which, if it were to occur, would make for an incredibly rare string of powerful storms in a part of the country that had seen relatively quiet and unusually mild weather since January.
These storms are occurring in a large-scale weather pattern that is favorable for inclement weather along the East Coast. This pattern includes a potent area of high pressure parked near Greenland, serving as a “block” to weather systems trying to move northeast, and out to sea.
In addition, a see-saw pattern of atmospheric pressure over the North Atlantic that meteorologists keep track of, known as North Atlantic Oscillation, or NAO, currently favors stormy weather.
When the NAO is in a negative phase, it is more favorable for snowstorms in the eastern U.S. and Europe. Lately, the NAO index has plunged to a record low, which is indicative of how primed the atmosphere is for major storms.