According to the National Weather Service, a polar vortex will impact most of the country this weekend, here is what you need to know.

It's going to get cold in Tennessee. Meteorologists predict freezing temperatures for much of the state. Here's the latest.

The polar vortex is expected to reach the Utah-Idaho border sometime in the late afternoon and evening Friday as it continues to move south. As it moves through parts of the state, it will produce small snow showers, bringing more snow to the region before drier conditions return.

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.

Are you ready for the coming arctic storm? Here’s the latest Colorado weather forecast and everything else you need to know ahead of extreme cold.

People living "basically anywhere from the Rockies eastward" will see extremely cold temperatures over the next several days, a meteorologist says.

VIRGINIA BEACH, Va. — Looking ahead to next week, a major arctic blast is expected to settle into Hampton Roads and Mid-Atlantic. The region will likely deal with the coldest weather so far this winter season.

The polar vortex is always around. It is a channel of strong winds high up in the atmosphere that circles the poles. One over the North Pole and one over the South Pole. When the vortex is at it's strongest, the vortex is well defined and has a single circular shape to it.

A polar vortex dipping down from Siberia will bring a cold front with frigid temperatures to nearly 300 million Americans. See maps of the arctic blast.

It’s going to be a rude awakening tomorrow — a full taste of winter, for sure,” National Weather Service meteorologist says

An arctic blast will send temperatures across the United States plummeting as bitterly cold air that originated in Siberia will arrive from Canada by week’s end, bringing with it dangerously cold wind chills for millions of Americans.