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

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

A dramatic blast of cold air may be coming for the United States in late January, courtesy of the polar vortex. Here's what ...

A polar vortex is expected to bring two surges of extremely cold air to the U.S. in January. Here's what to know in Middle ...

The polar vortex flooding into the US is set to deliver the coldest air on Earth to the northern half of the country, threatening millions with more dangerous winter conditions. Both snow and bitterly ...

A winter that feels more like spring in parts of the West is colliding with brutal cold and volatile storms elsewhere, leaving even seasoned forecasters warning that the United States is entering ...

Michigan is experiencing frigid temperatures and heavy snow due to a dip in the jet stream, not the polar vortex. The polar vortex is a large-scale cyclone of cold air that typically stays far north ...

Don't be fooled by the string of uneventful weather — the polar vortex is rebooting and will take another swing, or several, at the greater Philadelphia region, leading to a turbulent weather pattern ...

Add Yahoo as a preferred source to see more of our stories on Google. Michigan is set for several days of frigid temperatures and heavy lake-effect snow as Arctic air continues its slow march across ...

Add Yahoo as a preferred source to see more of our stories on Google. With over 170 million Americans facing below average temperatures, even colder air may be on the horizon thanks to the ...