A powerful storm system is sweeping across large parts of the United States, bringing heavy snow, freezing cold and strong winds from Montana to Maine and from Texas to Pennsylvania.

“Snow squalls pose serious threats to personal safety and property and produce costly transportation disruptions due to multi-vehicle pileups,” the NWS warns. “There is no safe place on a highway when snow squalls are approaching.”

A blizzard is a couple of giant steps above a winter storm. According to the National Weather Service, a storm officially qualifies as a blizzard when winds reach or exceed 35 mph and when the visibility drops to only a quarter mile or less. These conditions need to stay active for at least 3 hours.

The Patriots could derive a big advantage from the weather should snow touch down on Gillette Stadium on Sunday afternoon.

Severe winter storms bring heavy snow and dangerous travel across Great Lakes and Northeast. NWS warns of whiteout conditions, frigid temperatures, and near-blizzard winds in multiple states. Snow squalls threaten New Year's Eve travel across the Lower ...