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

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

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

Despite being notorious for bringing brutal cold and dangerous wind chills, the polar vortex has a surprising upside.

Niagara Falls has turned into a breathtaking icy landscape after a powerful polar vortex swept across the region, sending ...

The sudden blast may come as a shock to many Americans after a mostly mild start to winter, but that warmth may be partly ...

As the U.S. prepares to take on another bout of cold weather, the term "polar vortex" is getting thrown around. But what is ...

A winter storm descending on the US is expected to deliver heavy snow and ice to more than 150 million people across roughly ...

A crippling winter storm that could paralyze parts of the Southern and Central U.S. this weekend, and some of the effects ...

Alabama braces for another polar vortex blast bringing well below freezing temperatures. How cold will temperatures get? Here ...

Strong winds, frigid temperatures, and snowfall moved across several states during the course of the last few days, and for many, this latest storm marked the first impactful snow of the season.

The polar jet stream, which is affected by the polar vortex above it, has become quite wavy, allowing Arctic air to ...