A huge swath of the U.S. was blasted with ice, snow and wind on Monday as the polar vortex that dipped south over the weekend kept much of the country east of the Rockies in its frigid grip,

Temperatures plunged into the teens and single digits in some spots, and the snow-dusted winds are driving the wind chill below zero. The polar vortex, a swirling mass of Arctic air typically contained over the North Pole, has pushed south, driving bone-chilling temperatures into the eastern United States.

This can form what is called a Polar Vortex. This isn’t anything new, it’s just a newer term. This is when the area of high pressure moves south off the pole, hence polar and the jet dips even further south with an area of low pressure, which features wind moving around the low, hence vortex.