The cold temperatures are coming from a not uncommon expansion in the Polar Vortex, which are counter-clockwise rotating air currents that typically hang over the Arctic.

Abnormal weather events and severe winter storms could be caused by a disrupted polar vortex. Find out here how the polar vortex affects the weather.

However, a deep freeze, thanks to the polar vortex dipping down from Siberia, is about to bring even harsher arctic blast to nearly 300 million Americans starting this weekend. Maps show where and when the cold front will arrive.