The polar vortex, a mass of cold air over the Arctic, is beginning its seasonal strengthening. A strong polar vortex typically keeps the coldest air locked near the North Pole. A weaker or wobbling ...

The Earth's polar vortex is stirring up, bringing the first hints at changing weather as fall descends on the U.S. This movement means gradual cooling and a more active storm track across the northern ...

The polar vortex is beginning to stir, signaling a gradual shift toward cooler fall weather in the northern U.S. Tennessee is expected to see mild temperatures through December, with the average first ...