Does the thought of being blasted by Arctic air send shivers down your back? Well, bundle up — because the dreaded polar vortex is doing just that for much of the United States.
Here's more about what the polar vortex is — plus some mythbusters about what it's most definitely not.
What is the polar vortex?
The polar vortex is an area of low pressure and cold air that swirls around both of the Earth's poles like a wheel. Sometimes the polar vortex wobbles and a lobe surges south, blanketing portions of North America with bitter temperatures.
The chilly mass circulates around the North (and South) Pole all year long. In the winter, it weakens, sending cold air south with the jet stream.
The polar vortex lives high in the atmosphere and doesn't bring snow or ice with it, according to NBC News meteorologist Sherri Pugh.
"It's actually in the stratosphere. Our weather happens in the lower level of the atmosphere, and this occurs just right above that lower level," Pugh said.
Is the polar vortex a new phenomenon?
While the record-breaking cold of January 2014 may have been the first time you heard about the polar vortex, the phenomenon itself has been around forever. According to Weather Channel senior meteorologist Stu Ostro, the term was even used before the Civil War.
And the polar vortex exists even when you don't feel its effects.
"The polar vortex doesn't come and go. It does weaken and strengthen, and that's how it fuels the weather around the world," Pugh said.
How low do temperatures go?
It depends. But this particular bout of cold air doesn't look set to break any records.
"While you're dealing with subzero temperatures at the pole, it does modify, fortunately, as it comes further south," Pugh said. "Higher latitudes such as the Dakotas can get single digits. Here in the Northeast, it won't be quite as cold. We'll get more of the teens."
But with the wind chill, temperatures can feel significantly more punishing.
"If you add just a little bit of wind, it can really make it feel so much more brutally cold. It doesn't take a lot of wind once we get so cold for it to feel even worse. So while the temperatures are cold enough to begin with, you can add a little wind chill to make it absolutely bitter," Pugh said.
Is America the only place that experiences the polar vortex?
Hardly. The chill we feel passes through Canada first. And the polar vortex delivers cold air to Europe and Siberia, plus other parts of Asia, too.
Is the polar vortex tied to climate change?
The polar vortex is totally separate from global warming and climate change.
"Climate change is not based on a single event like a polar vortex-induced cold snap. It's measured over a long period of time and government statistics, going back to 1880 when record-keeping began, show that on average, the world's annual temperature has been ticking upward," TODAY's Al Roker said.
Climate change also hasn't affected the frequency of how often we experience the polar vortex or the temperatures associated with it, Pugh said.
"While some [other weather] events are signatures of a warming planet, this is not one of those events, and we do not give attribution to climate changes for the swings in the polar vortex," she said. "It's been a phenomenon that has been studied for decades now."
Stay warm during the polar vortex with these tips for avoiding frostbite and hypothermia from the National Weather Service.