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

Major cities across the Northeast and Midwest are facing temperatures 10-20 degrees below average, according to forecasters.

A fresh blast of Arctic air is poised to spill across a wide swath of the United States, and the latest polar vortex map ...

Cold temperatures are expected to last through the end of the month — and forecasters say that there's a potential for snow ...

The first cold wave will reach the East Coast on Thursday, followed by another surge of frigid air this weekend and more next ...

Severe winter chill is expected to plunge central and eastern states into below average temperatures as the polar vortex ...

Colder air is returning to the central and eastern U.S. as the polar vortex becomes more active, bringing fluctuating ...

The displaced polar vortex will bring prolonged periods of cold to the eastern portion of the Lower 48 through the end of ...

A significant portion of the U.S. is experiencing below-average temperatures due to a disrupted polar vortex, affecting over ...

Don't let the incoming string of relatively warm days in the greater Philadelphia region fool you; the polar vortex is still ...

With over 170 million Americans facing below average temperatures, even colder air may be on the horizon thanks to the ...

Arctic air originates near the polar regions and is among the coldest air masses on Earth. It typically stays locked in ...