Is Polar Vortex Bringing Another Hard Winter?

The northeast of the US could be facing another extreme winter thanks to the polar vortex, a long range weather forecaster has suggested.

Paul Pastelok, long-range forecast expert for AccuWeather.com, said cold air and high snow amounts will define the winter season for many.

In an interview on the site he said the polar vortex, the culprit responsible for several days of below-zero temperatures last year, will slip down into the region from time to time, delivering blasts of Arctic air.

"I think, primarily, we'll see that happening in mid-January into February but again, it's not going to be the same type of situation as we saw last year, not as persistent.

"The cold of last season was extreme because it was so persistent. We saw readings that we haven't seen in a long time: 15- to 20-below-zero readings."

He suggested that higher-than-normal snow levels are possible west of the I-95 corridor.

1/11

Gallery: Polar Vortex Returns

Morning snow makes Washington's Capitol even more picturesque than usual
Snow blankets the White House grounds
Some make the most of the weather, indulging in winter passtimes
The cold no doubt makes this US Marine's task of guarding the White House a little more arduous
The sub-zero temperatures have emptied out Washington's parks
Few brave it out on foot in the cold
In Minneapolis, Minnesota, temperatures dropped to -4F (-20C)
Scientists say this is the coldest winter in Minnesota for 35 years
A member of the US military honor guard walks past gravestones at Arlington National Cemetery in Virginia
A water vapor view of the United States shows a cold mass of arctic air bringing temperatures 10 to 30 degrees below average
This false-colour satellite image, with ice appearing in blue, shows the Great Lakes frozen over by plummeting temperatures

"Places like Harrisburg, down to Hagerstown getting into the mountains, the Appalachians, I think that's where you're going to see your bigger, heavier amounts," said Mr Pastelok.

He added: "I'm very concerned about the Tennessee Valley to the Gulf Coast as far as extremes go this year."

He said that overall, the region will have a very wet winter, but could also see "ice events".

Video: T-Shirt Freezes In Polar US Temps

Last winter huge areas of the US saw record cold weather, with the Great Lakes frozen over and extreme temperatures as far south as Alabama.

The polar vortex is a rotating pool of cold, dense air held in place by a belt of strong winds which last year slipped to bring extreme weather to as many as 180 million Americans.

Sky News weather producer Rebecca Yussuf urged caution. She said: "Seasonal forecasting is still in its infancy and is largely seen as experimental and complex.

1/12

Gallery: Niagara Falls Frozen By Polar Vortex

Icicles hang from the US side of the Niagara Falls, caused by record-breaking low temperatures that have gripped North America.
The Niagara River, with the Rainbow Bridge in the background, froze over as a weather system known as a polar vortex swept north.
Visitors came equipped with SLR cameras to capture the unusual sight.
Water continued to flow over the waterfalls, carrying with it chunks of ice.
Huge icy boulders formed at the base of the 34-metre-tall American Falls.
Tourists made the most of the unusually cold weather, with rising temperatures expected to allow frozen states to thaw over the coming days. Click through for more pictures.

"Seasonal forecasts are not like the 1-5 day forecasts we are used to, instead they look at the probabilities of various outcomes.

"The forecast produces a most probable outcome, but this outcome is not necessarily what will happen in reality.

"It is therefore too early to give a definitive forecast for the coming winter across the USA."