How cold is much of the U.S. going to be in the days to come? Cold enough to discourage hardy fans of the Green Bay Packers—who have sold out 319 games in a row, dating back to 1983—from attending an NFL playoff game at Lambeau Field. Temperatures for Sunday afternoon’s wild-card matchup between the Packers and the San Francisco 49ers could be -18º F (-28º C) or even lower. That would rival the famous “Ice Bowl,” the 1967 NFL championship game between the Packers and the Dallas Cowboys, which is believed to be the coldest game in NFL history. Even though Green Bay was just able to avoid a TV blackout of Sunday’s game—NFL rules state that a game must be sold out to be televised in the home team’s market—the last tickets were bought not by Packers fans, but by corporate partners. But can you blame Green Bay fans? Even Cheeseheads are subject to frostbite.
But Wisconsin won’t be the only place suffering through potentially record-breaking cold in the days to come. Dangerously cold temperatures will be hit the Northern Plains and the Upper Midwest this weekend and into next week, causing temperatures to fall below 0º F (-18º C), and in some places, reach -60º F (-51º C) with the wind chill. In Chicago, temperatures on Monday could threaten the all-time coldest daily high temperature in the city’s history: -11º F (-24º C), reached on Christmas Eve 1983 and Jan. 18, 1994. Detroit could see its all-time coldest daily high temperature record of -4º F (-20º C) tumble as well. That cold air will continue towards the East Coast in the following days, with temperatures in the single digits over the mid-Atlantic, and in the -10s and -20s in parts of New England by mid-week. Altogether this could be the coldest Arctic air mass to hit the middle of the country in more than 20 years, with temperatures as much as 40º F (22 º C) below normal in much of the country.
The cause of the Arctic outbreak can be traced to northeastern Canada and Greenland, where an area of high pressure and relatively mild temperatures is set to block the eastward progression of weather systems, like an offensive lineman protecting the quarterback from the other team.
The atmospheric blocking is forcing a section of the polar vortex to break off and move south, into the U.S. The polar vortex is an area of cold low pressure that typically circulates around the Arctic during the winter, spreading tentacles of cold southward into Europe, Asia, and North America at times. Except this time, it’s not a small section of the vortex, but what one forecaster, Ryan Maue of WeatherBELL Analytics, called “more like the whole enchilada” in a Twitter conversation on Thursday.
It’s worth noting that even as much of the U.S. shivers, temperatures in Greenland are just about normal—a reminder that while weather may be local, climate is global. And while the U.S. cold snap is historic in its own right, it’s going to feel that much colder because, quite simply, we’ve forgotten how freezing winter can be. While the U.S. as a whole has warmed by about 1.3º F (0.71º C)over the past 100 years, winter has seen the fastest warming. Winter nights across the country have warmed about 30% faster than nights over the whole year. Since 1912, the coldest states have warmed nearly twice as fast as the rest of the country. In a warming world, winter loses its sting.
But it won’t seem that way over the next few days—and that will be dangerous. Even with climate change, the U.S. still generally still sees more deaths from cold snaps than from extreme heat. For all the media attention that snow gets—looking at you, Weather Channel—extreme cold can be deadly, especially for the society’s most vulnerable. For them, a little global warming can’t come soon enough.