The Polar Vortex is expected to be impacted by a Sudden Stratosphere Warming, bringing cold air to the eastern US.

A winter buzzword, explained.

Much of the nation east of the Rocky Mountains is hunkered down for what could be the worst winter storm of the season.

The west half of the country, including the Midwest, will start to warm up. But that won't be the case for the East Coast.

Rising Arctic temperatures and melting sea ice could be causing cold air to flow into the Northern Hemisphere. But not all scientists agree.

A collapse in the polar vortex is letting Artic air come here. What that means, and why it happens.

This winter’s harsh run in the East is intensifying, with some of the coldest air so far this season plunging into Vermont this weekend.

(CNN) — High above the North Pole, in a slice of atmosphere rarely noticed and even less understood, a transformation is underway. Over the next 10 days, changes in the stratosphere will upend weather ...

This winter’s harsh run is intensifying, with some of the coldest air so far this season plunging into New Hampshire.