The polar vortex is beginning to stir, signaling a gradual shift toward cooler, autumnal weather in the northern U.S. While temperatures are expected to cool, the Climate Prediction Center forecasts ...

NORFOLK, Va. — Have you ever wondered why some winters are mild while others bring freezing temperatures and snowstorms? One of the key players in these dramatic shifts is something called the polar ...

WASHINGTON (7News) — Early indications of a weakening polar vortex could send Arctic air into North America next month. Much of the U.S. is overdue for some cold air and winter-like temperatures as ...

NASA instruments captured the moment part of the sun appeared to break off from the giant star and get swept up in a polar vortex. But according to the scientist who drew attention to it, it's not as ...

First, there was a bitter Arctic outbreak. Next up will be a thaw. But thereafter, it may come down to what the polar vortex does — and the jury is still out on that. To say that January has been a ...

The frigid stream of air that plunged down into the Central U.S. this week is breaking cold records from South Dakota to Texas, with temperatures in the single digits setting records in many locations ...

The vortex is strongest during the winter and usually weakens or even disappears in the summer. When the polar vortex weakens or even splits, it allows frigid air to escape and push southward toward ...