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

When parts of the vortex break down, lobes of Arctic air can drift south, guided by changes in the jet stream. This allows ...

Thanks to the polar vortex, the first half of December will bring multiple waves of Arctic air to the U.S. Here's what to ...

When the polar vortex stumbles, the weather at ground level can pivot from mild to brutal in a matter of days. A circulation ...

A strong polar vortex doesn't cause cold weather — it does the opposite. Here's what to know about polar vortices, how they work.

Those struggling with high heating bills due to relentless cold and sore backs from shoveling snow in the Midwest and ...

The Polar vortex is causing temperatures to plummet dangerously across the Philadelphia region, and frostbite could become a ...