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.

Preparations are underway as an arctic blast dives into the nation's interior and southern regions and pushes a snowstorm into the Mid-Atlantic and Northeast that will be followed by lethal cold.

A dangerous and potentially life-threatening stretch of cold weather has much of the U.S. on alert as a lobe of the polar vortex invades the nation and sends temperatures tumbling to levels not seen in years.