Polar vortex

A ’very active pattern' is hitting the United States starting Friday, says the National Weather Service.

Tens of millions of Americans are currently under freeze warnings or watches, say federal forecasters.

As first glance, asking whether global warming results in more snow may seem like a silly question because obviously, if it gets warm enough, there is no snow.

A ’very active pattern' is hitting the United States starting Friday, says the National Weather Service.

Tens of millions of Americans are currently under freeze warnings or watches, say federal forecasters.

As first glance, asking whether global warming results in more snow may seem like a silly question because obviously, if it gets warm enough, there is no snow.