A nor'easter could be on the way this week. How likely is the 1st snowfall of the season?
· Yahoo NewsA nor'easter could be on the way later this week, bringing rain, gusty winds and a chance of the season's first snow to parts of the Northeast and Great Lakes.
The National Weather Service's Weather Prediction Center (WPC) said it is highly likely that a storm will develop over the Ohio Valley on Wednesday, and could bring thunderstorms and gusty winds from the Midwest to the Ohio and Tennessee Valleys as it moves east. Later, it will shift off the Mid-Atlantic coast and is projected to strengthen Friday.
"Drastically colder air" is also forecast to surge into the eastern half of the country by Wednesday night, the WPC said, with increasing winds by Thursday morning and wet snow possible in the upper Great Lakes. Nearly 200 million people across the eastern half of the country will experience their coldest temperatures since spring, CNN reported.
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The WPC said much colder air will rush south across the Great Lakes, bringing snow showers, while the storm itself is forecast to bring "a cold rain and potential inland snow for the Central Appalachians."
While forecasters are confident a storm will form, the WPC said its exact track and impacts are not yet known.
Is snow likely?
The first snow of the season looks most likely for those in the mountains, according to the WPC, where potential inland snow could be seen in the Central Appalachians, running through Pennsylvania, Maryland and West Virginia.
AccuWeather reported that Pittsburgh, as well as Syracuse and Binghamton in New York, could also see their first flakes of the season. The mountainous regions of the Poconos, Catskills and Berkshires could also see snow.
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"This storm will likely bring the first snowflakes of the season to many locations, though the exact track and intensity of the storm will dictate where," AccuWeather senior meteorologist Adam Douty said.
Most coastal areas and lower-lying parts of the Northeast are more likely to see rain than snow. The WPC puts eastern Pennsylvania at roughly a 10% chance of at least an inch of snow between Thursday and Saturday evening.
Is the nor'easter linked to the polar vortex?
The early weakening of the polar vortex, which started last week, has left many wondering whether a blast of icy weather is on its way as a result. But forecasters have said it's not that clear.
Tyler Roys, a meteorologist at AccuWeather, told Yahoo it is "hard to say if there is any connection between the two." He said most of the impacts from an early polar vortex disruption are "going towards eastern Europe and Asia."
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If the vortex has any influence, Roys said, it is likely tied to the cold arriving behind the storm, though "the influence of the polar vortex appears to be limited."
Roys added that forecasters "do feel that there could be an increase of influence from the polar vortex towards the end of November into December" as the current pattern fades and a new one sets up.
Laura Ciasto, a meteorologist at the National Oceanic and Atmospheric Administration (NOAA), told Yahoo that the vortex has been "displaced for well over a week," though it hasn't yet reached the threshold for a sudden stratospheric warming, a rapid warming high in the atmosphere that can weaken or split the vortex.
"It's possible we are seeing that effect at the surface now," she said. "It's a classic chicken-or-the-egg situation."
What is a nor'easter?
A nor'easter is a storm situated along the East Coast of the U.S., with its namesake reflecting that the winds over the coastal area are usually from the northeast, the NWS says.
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It forms when an area of lower air pressure draws in surrounding air and strengthens near the coast. It is often fueled by the clash of cold air from the north and warm, moist air over the Gulf Stream.
While these storms can happen at any time of year, they are usually at their strongest between the colder months, from September through April.
Nor'easters "nearly always" bring precipitation in the form of heavy rain or snow, the NWS says, as well as winds of gale force, rough seas and, sometimes, coastal flooding.
The most violent nor'easters have caused billions of dollars in damage. The storm is expected to be less severe than September's early-season nor'easter, which killed a New York City Housing Authority worker, flooded coastal communities and left more than 130,000 customers without power across the Northeast and mid-Atlantic, the Associated Press reported.