What is a polar vortex? US gets a taste of the Arctic this week

The “polar vortex” normally keeps some of the coldest weather bottled up near the North Pole. But this winter has not been normal.

​The “polar vortex” normally keeps some of the coldest weather bottled up near the North Pole. But this winter has not been normal.   The “polar vortex” normally keeps some of the coldest weather bottled up near the North Pole. But this winter has not been normal.