The polar vortex of ultra-cold air usually spins around the North Pole, but it sometimes ventures south into the U.S., Europe and Asia. Some experts say such cold air outbreaks are happening more frequently, paradoxically, because of a warming world.

An area stretching from Texas to Tennessee braced Wednesday for the possible arrival of freezing rain and snow even as some parts of the U.S. hit by the plunging polar vortex this week began to shake off its icy effects.

An area stretching from Texas to Tennessee braced Wednesday for the expected arrival of freezing rain and snow, as some other parts of the country that already received an arctic blast this week prepared to go another round with the plunging polar vortex.

as some other parts of the country that already received an arctic blast this week prepared to go another round with the plunging polar vortex. Arkansas' capital, Little Rock, closed schools on ...

A winter storm sweeping through the U.S. South on Tuesday was dumping snow at levels millions of residents haven’t seen before. Moisture from the Gulf of Mexico was combining with a

LITTLE ROCK, Ark. — Very cold arctic air has filtered into Arkansas, with the coldest impacts expected Sunday night through Wednesday morning. Due to the nature and duration of the extreme cold, a Weather Impact Alert is in effect now through noon Wednesday.

DENVER — A powerful arctic cold front arrived in Colorado on Friday and will keep the state very cold until Wednesday. The 9NEWS Weather Impact Team has issued 9NEWS Weather Impact Days for ...

Snow is expected to taper off around Denver by the early afternoon, while temperatures will remain well-below freezing through Monday night.

A new blast of Arctic air sweeping from north to south will bring bone-chilling temperatures to millions of Americans this weekend and next week.

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is about to bring even harsher arctic blast to nearly 300 million Americans starting this weekend. Maps show where and ...

This will be due to a polar vortex, an area of strong winds that encircle the Arctic and typically keeps the coldest air locked near the Pole, according to the FOX Forecast Center. This weekend ...

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is about to bring even harsher arctic blast to nearly 300 million Americans starting this weekend. Maps show where and ...