The eastern two-thirds of the U.S. is bracing for its most extreme winter storm of the season. Meteorologists warn that damage from this system could rival that of a major hurricane. To understand why it’s expected to be so powerful, we must look toward the rapidly changing Arctic.

As greenhouse gas emissions drive global temperatures higher, the Arctic is warming nearly four times faster than the rest of the planet. This has led to unprecedented sea ice loss and altered atmospheric circulation patterns that set the stage for the Arctic blast that will fuel this weekend’s storm.

That frigid air mass is currently spreading sub-zero and single-digit temperatures eastward across the country. When it collides with an atmospheric river streaming from the Pacific Ocean and Gulf of Mexico, it will unleash a major winter storm expected to pummel a 2,000-mile (3,200-kilometer) stretch of the eastern U.S. with snow and ice.

The storm’s impact will extend from the Central-Southern Plains to the East Coast starting Friday and lasting through the weekend. As of Thursday morning, the National Weather Service had placed most of the country under various winter weather advisories.

How Arctic warming can fuel severe winter storms

Arctic blasts occur when the normally tight circulation of cold air and low pressure over the North Pole—the polar vortex—becomes distorted, allowing frigid air to spill southward into the mid-latitudes. Meteorologists describe this configuration as a “stretched” polar vortex.

“In our research, we have demonstrated that polar vortex stretching events have accelerated in the era of accelerated Arctic change,” Judah Cohen, an MIT climatologist, told Gizmodo in an email. “Climate change in general, but Arctic change in particular, is favorable for forcing these events.”

Arctic amplification—the exceptionally rapid warming of the Arctic—causes high-pressure “ridges” to build over the Urals and Barents-Kara Seas while low-pressure “troughs” form over East Asia, Cohen explained. This atmospheric pattern is favorable for forcing polar vortex stretching events that often send extreme cold southward into Canada and the U.S.

Global climate models show that increased snow cover in Eurasia and reduced sea ice extent in the Barents-Kara Seas drive the atmosphere to produce more polar vortex stretching events. These disruptions often send colder temperatures across Asia and North America about one to two months later, Cohen said.

The Arctic blast currently impacting the U.S. is a perfect example of these dynamics at work. This fall and winter, sea ice has been at a record low in the Barents-Kara Seas, and snowfall has been heavy in Siberia, according to Cohen. He believes these conditions helped trigger the polar vortex stretching event now bringing extreme cold to the U.S. and fueling the weekend’s winter storm.

The latest storm forecast

Dangerously cold Arctic air will expand into the North-Central Plains, Upper Midwest, and Great Lakes today, then spill out into the Southern Plains, Mississippi Valley, and Midwest tonight, according to the NWS. Gusty winds will send wind chills plummeting as low as -50 degrees Fahrenheit (-45 degrees Celsius) across the Northern Plains.

On Friday, the Arctic blast will converge with an atmospheric river—a narrow band of concentrated moisture in the lower atmosphere—to the south. This will cause the abundant water vapor to rapidly rise, cool, and condense into wintry precipitation, producing a severe winter storm that will track from the Southern High Plains and Rocky Mountains into the Northeast over the weekend.

Meteorologists expect heavy snow and damaging ice accumulations to cause widespread power outages and significant travel disruptions across the East. Extremely cold temperatures tracking behind the storm could create a dangerous situation for anyone suddenly unable to heat their homes or snarled in weather-related road traffic.

Researchers like Cohen are still unraveling the complex relationship between global climate change, polar vortex behavior, and extreme mid-latitude weather. But this approaching storm serves as a clear example of how the impacts of Arctic warming can stretch far beyond the North Pole, influencing weather patterns thousands of miles away.