Atmospheric scientists were surprised earlier this month to notice that the Arctic's polar vortex reversed its trajectory as it began spinning in the opposite direction. What's more: It has yet to ...

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.

The polar vortex is a large area of cold air high up in the atmosphere that normally spins over the North Pole (as its name suggests). It usually keeps the coldest air locked up in the Arctic.

Dust off the parkas. After a mild December, the polar vortex is set to send an arctic blast into the US later this week. “That polar jet will be pushed further south, and guess what that does ...

A map showing a Polar Vortex that could effect eastern North America in February. X/Judah Cohen “For the first half of January, that polar vortex kind of stumbled and fell foul there, moved south.

When the Arctic's polar vortex is strong it stays parked at the North Pole (left); when it weakens, however, it can move southward, as it did in January 2014 (right). (Image credit: NASA) ...

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.

The most bone-chilling blasts of cold air experienced in the United States can be blamed on a weather phenomenon that typically dominates a region 3,000 miles away.