Winter Vortex

As the U.S. Midwest and East Coast thawed out from days of bitter, deadly cold, Californians on Friday battened down the hatches ahead of a fierce winter storm carrying heavy rains and high winds that could touch off urban flooding and mudslides.

Polar vortex: Nearly 90 million people are likely to experience temperatures at or below zero in the Midwest and New England, according to the National Weather Service; 25 million of them will face temperatures below minus-20 - dips that when combined with wind can cause frostbite in a matter of minutes.

Two-thirds of the continental United States will be a frozen ice box, as the so-called polar vortex of frigid arctic air spins across the U.S. Midwest, clips the Great Lakes, the Ohio Valley and pushes on into New England.

It was too cold to, among other things, ice skate Thursday morning. Washington woke to its coldest December morning in almost a decade, and the frigid and the frightened braced for what promises to be the chiliest stretch of winter in two years.

Canada and the northern United States were suffering their first brutal cold spell of the season Friday, after a frigid mass of Arctic air -- the dreaded "Polar Vortex" -- settled over the region.

Winter's first polar vortex blast, already taking shape in the Arctic this weekend, targets the Lower 48 next week. By Tuesday, temperatures below zero will plunge south into the northern plains and Midwest. Over the course of a few days, the cold air will blast across the country to the Northeast.

An arctic blast eased its grip on much of the eastern U.S. on Wednesday, with winds calming and the weather warming slightly.

Just how cold is it in Kentucky? Apparently cold enough for an escaped prisoner to decide to turn himself in.

The bitter chill gripping North America is a result of Arctic air that has spilled southwards, and global warming may be a cause.

A deadly chill had much of the United States and Canada in its wintry grip on Tuesday, as a record-breaking cold snap brought temperatures lower than on the surface of Mars.

Dangerously cold polar air snapped decades-old records as it spread on Tuesday from the midwest to southern and eastern parts of the US and eastern Canada, making it hazardous to venture outside and keeping many schools and businesses closed.

The coldest, most dangerous blast of polar air in decades gripped the U.S. Midwest and pushed toward the East and South and eastern Canada on Monday.

As the U.S. Midwest and East Coast thawed out from days of bitter, deadly cold, Californians on Friday battened down the hatches ahead of a fierce winter storm carrying heavy rains and high winds that could touch off urban flooding and mudslides.

Polar vortex: Nearly 90 million people are likely to experience temperatures at or below zero in the Midwest and New England, according to the National Weather Service; 25 million of them will face temperatures below minus-20 - dips that when combined with wind can cause frostbite in a matter of minutes.

Two-thirds of the continental United States will be a frozen ice box, as the so-called polar vortex of frigid arctic air spins across the U.S. Midwest, clips the Great Lakes, the Ohio Valley and pushes on into New England.

It was too cold to, among other things, ice skate Thursday morning. Washington woke to its coldest December morning in almost a decade, and the frigid and the frightened braced for what promises to be the chiliest stretch of winter in two years.

Canada and the northern United States were suffering their first brutal cold spell of the season Friday, after a frigid mass of Arctic air -- the dreaded "Polar Vortex" -- settled over the region.

Winter's first polar vortex blast, already taking shape in the Arctic this weekend, targets the Lower 48 next week. By Tuesday, temperatures below zero will plunge south into the northern plains and Midwest. Over the course of a few days, the cold air will blast across the country to the Northeast.

An arctic blast eased its grip on much of the eastern U.S. on Wednesday, with winds calming and the weather warming slightly.

Just how cold is it in Kentucky? Apparently cold enough for an escaped prisoner to decide to turn himself in.

The bitter chill gripping North America is a result of Arctic air that has spilled southwards, and global warming may be a cause.

A deadly chill had much of the United States and Canada in its wintry grip on Tuesday, as a record-breaking cold snap brought temperatures lower than on the surface of Mars.

Dangerously cold polar air snapped decades-old records as it spread on Tuesday from the midwest to southern and eastern parts of the US and eastern Canada, making it hazardous to venture outside and keeping many schools and businesses closed.

The coldest, most dangerous blast of polar air in decades gripped the U.S. Midwest and pushed toward the East and South and eastern Canada on Monday.