Polar vortex could impact the US this winter: What it means for NY temperatures

STATEN ISLAND, NY — If you’ve been keeping a tab on winter forecastsyou’ve likely heard the term “polar vortex” and the potential impact it may have on the upcoming season. But exactly what is the polar vortex and what does it mean for New York residents this winter?

Fortunately, Paul Pastelok, an AccuWeather senior meteorologist and lead US long range forecaster, spoke to the Staten Island Advance/SILive.com and clarified the role the polar vortex could play in the winter of 2024-25. Where it stands, the polar vortex may result in an extended blast of arctic air in the US at the tail end of the season.

What is the polar vortex?

The polar vortex is a “constant feature” that begins to “show up” sometime in September and typically persists through April or May.

Pastelok said the polar vortex is an area of ​​low pressure in the upper layers of the atmosphere that rests over the polar region.

“The rotation normally is out of the counter-clockwise direction because it is an area of ​​low pressure,” Pastelok said. “And so, when the polar vortex strengthens and becomes strong over the pole, typically what happens as a result of that is that most of the cold is captured and concentrated over the polar region.”

When this happens, those areas in the middle latitudes, including the US, generally experience a west-to-east air flow and typical cool, potentially mild, temperatures, according to Pastelok.

A strong polar vortex bottles up all that arctic air over the polar region, preventing any of the chill from seeing out. However, meteorologists such as Pastelok monitor the vortex to see if they can predict any disruptions, which could result in some of that cold air leaking into the US

Pastelok and colleagues in the meteorological field monitor to see if there are any influxes of warm air that breach the stratosphere (the layer above the troposphere, where we live) and impact the polar vortex circulation.

When these influxes affect the polar jet stream, the circulation is disrupted. Pastelok says “bumps” and “grooves” begin to develop then, allowing cool air to escape the polar region.

“First of all, it would have to kind of come down to the lower levels, and then air masses around it push it and move it around across the globe,” said Pastelok.

Should this leak occur, the encroaching arctic air could cause a disruptive pattern that persists for three to five consecutive weeks, he said.

“It’s not a short-term event where you get a cold front followed by a cold snap for a couple of days,” Pastelok said.

The polar vortex forecast for winter 2024-25

As detailed in the latest AccuWeather winter forecastmuch of the nation, including NY, is in store for a more temperate season. However, a potential disruption of the polar vortex could result in a spike of cool air sometime at the end of winter.

Although it is very difficult to predict a disruption in the polar vortex months in advance, Pastelok says that examining conditions from years past provides an idea of ​​the probability of the polar vortex impacting weather in the US

“This year, the setup, when you look at the research, is not for frequent disruptions of the polar vortex,” said Pastelok. “In fact, it looks very strong in the middle of the wintertime period, like in January, and we should expect a lesser chance for the polar vortex to have an influence or impact on our area.

It is towards the end of the winter that a couple of big events in the past have caused major disruption, research shows, and that would mean we could see a period of unsettled weather at winter’s end, he said.

Despite this early outlook, Pastelok said the vortex may not necessarily impact North America; Any disruptions could end up hitting Europe or Asia. Ultimately, the weather systems in place at the time of the disruption will steer the arctic air, preventing any specific forecast this far out.