Much below normal temperatures should persist across the eastern U.S. into early February before moderating slightly.

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 ...

To understand what Americans are experiencing with this winter blast, we need to look more than 20 miles above the surface of ...

Much of the nation east of the Rocky Mountains is hunkered down for what could be the worst winter storm of the season.

The Earth's polar vortex is stirring up, bringing the first hints of changing weather as the autumn foliage starts to turn and the temperatures begin to drop. The movement means gradual cooling and a ...

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 ...

A chilling polar vortex is set to bring snow and ice to the South and East this week. We show where.

The polar vortex is a large area of cold, spinning air that sits near the North Pole and exists year-round. When it weakens or shifts, Arctic air can spill south, increasing the risk of snow and ...