Around 140 million people across more than two dozen states people may experience temperatures greater than 70 degrees. Here are the places that are on T-shirt and shorts watch.

Research has found that rising temperatures in the Arctic are weakening weather systems that normally trap the cold around the poles, making winter weather more chaotic.

These severe cold events occur when the polar jet stream – the familiar jet stream of winter that runs along the boundary between Arctic and more temperate air – dips deeply southward, bringing the cold Arctic air to regions that don’t often experience it.

If someone asked you, “Where can I go in the United States to escape the frigid air this January?” what would you say?

Understanding the Polar Vortex The polar vortex is like a massive whirlpool of frigid air moving around our planet's poles. Think of it as a barrier that, when strong, keeps icy polar air trapped up north.

The polar vortex can be a powerful source of winter weather, but it's not the only cause of severe cold and snow in regions better known for warmth and sunshine. The Gulf Coast states are still digging out of the snowdrifts, but at least warmer temperatures are on tap heading into the weekend.

Police officers, residents and volunteers from across the state plunged into cold waters Saturday afternoon in an effort to raise money for Special Olympics Oklahoma. This polar plunge took place ...