A massive winter storm is battering much of the United States with freezing temperatures, powerful winds and heavy snowfall. The phenomenon has already claimed the lives of almost a dozen people, and more than a million customers lost electricity service. With thousands of flights cancelled, the storm also ruined the plans of many Americans traveling for Christmas. Anthony Reynes, a senior meteorologist with the National Oceanic and Atmospheric Administration (NOAA), explains how much longer the effects of the storm will last.