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

Michigan is set for several days of frigid temperatures and heavy lake-effect snow as Arctic air continues its slow march ...

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

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

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

Ben Gelber, a meteorologist for NBC4 in Columbus, Ohio, and a Pocono native, said the polar vortex is a large, circular pool ...

The Arctic Oscillation is a metric used to describe the strength of the polar vortex, or mass of arctic air that rotates ...

The brief respite of a January thaw is over as a significant pattern shift readies a return to harsh winter conditions across ...

In the coming weeks, cold air will continue for parts of the U.S. thanks to the influence of the polar vortex.

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

TOLEDO, Ohio (WTVG) - The polar vortex is a large area of low pressure encompassing the Earth’s poles. It can weaken and split up, causing the polar jet stream to move southward. This pushes cold ...