Forecasters say that the polar vortex will usher in waves of frigid air across parts of the U.S. through January. The “more active polar vortex will drive colder air and snow across the central and ...

Arctic air is expected to bring “near record cold” along with “dangerous wind chills” as it tracks south from the Northern High Plains on Friday, spreading into the Central Plains and Ohio Valley on ...

Michigan and the Great Lakes are bracing for another cold shot later this month — down to single digits in places — as a polar vortex split in the stratosphere nudges frigid Arctic air southward.

The stratospheric polar vortex, the winter engine that traps Arctic cold high above the North Pole, is entering its seasonal collapse. What's left is the lower-level polar vortex core, lingering over ...