A polar vortex — a swell of cold air and low pressure that typically swirls above the North and South Poles — descended from Siberia into the northern U.S. on Jan. 18, according to CBS News.

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is bringing an even harsher arctic blast to million Americans this week. Maps show what to expect as the cold front ...

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is bringing an even harsher arctic blast to million Americans this week. Maps show what to expect as the cold front ...

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 ...

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 and ...

Knoxville could be hit with another snowfall this weekend, and very cold temperatures are coming. The National Weather Service in Morristown cited an 80% chance of rain Jan. 18 and a 70% chance of ...

The bitter weather – tied to an Arctic “polar vortex” blast – is expected to bring night-time lows as cold as minus 31 deg C over the weekend for some of the northernmost parts of the US.

The bitter weather -- tied to an Arctic "polar vortex" blast -- is expected to bring nighttime lows as cold as minus 23 degrees Fahrenheit (minus 31 degrees Celsius) over the weekend for some of ...

"Have a cold weather survival kit if traveling." Driven by the jet stream, part of the polar vortex — a large area of cold air that spins over the North Pole in the winter — will drop about ...