High above the North Pole, in a slice of atmosphere rarely noticed and even less understood, a transformation is underway. Over the next 10 days, changes in the stratosphere will upend weather ...

The west half of the country, including the Midwest, will start to warm up. But that won't be the case for the East Coast. Here's the forecast.

In yet another sign that winter weather is either here or will be soon, the dreaded polar vortex is making news yet again. Its potential arrival in the United States over the next few weeks is cause ...

The polar vortex is sending arctic blasts and chilly temperatures to most of the United States, and states from Texas to Oklahoma could see snow, sleet and ice. As of Wednesday, Jan. 21, millions of ...

Summer may end on a cooler note for parts of the U.S., with meteorologists suggesting that a weakened polar vortex could usher in below-average temperatures as September begins. In contrast to earlier ...

WASHINGTON — A pattern flip that could send extreme cold air spilling into the region this winter may take shape. The polar vortex, which traps cold air near the North Pole, may experience a ...

This winter’s harsh run is intensifying, with some of the coldest air so far this season plunging into New Hampshire.

When the polar vortex stumbles, the weather at ground level can pivot from mild to brutal in a matter of days. A circulation that usually spins quietly above the pole can suddenly send lobes of Arctic ...