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.

Impact on North America's weather in March - An in-depth look at the forecasted polar vortex collapse and its potential effects on weather patterns across North America this March

A polar vortex collapse is expected over the next two weeks, with experts warning the weather phenomenon could send mercury plummeting across North America. The shock meteorological change is predicted to develop in mid-March,