Winter weather lingers as a major shift in the weather pattern could have millions across the United States once again reaching for their winter coats later this month before milder springlike air arrives for good.

Winter isn't over just yet. A major shift in the weather pattern could have millions across the United States once again reaching for their winter coats later this month before milder springlike air arrives for good.

A polar vortex collapse. Now, meteorologists are calling for another collapse in the middle of March, one that could plunge the U.S., Canada, and parts of Europe into a bitterly cold spell just days before the official arrival of spring.