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.

New York City got its first snow of the season on Tuesday as a powerful polar vortex swept across the eastern half of the country, bringing frigid temperatures. Highs are not expected to break out of ...

Rising Arctic temperatures and melting sea ice could be causing cold air to flow into the Northern Hemisphere. But not all ...

The polar vortex is weakening, and pockets of cold air are expected to break off and travel south into the United States — with some Arctic air expected to encroach on New England after Thanksgiving, ...

A potential wobble in the polar vortex could bring frigid Arctic air to the northern U.S. around Thanksgiving. Forecasts show below-average temperatures for about half the country, while the Southeast ...