Weather experts are sounding an alarm for more than a dozen states and warning people not to make travel plans over the weekend as a powerful winter storm is set to sweep across most of the eastern half of the U.S.

As much as 20 inches of heavy snow, sleet, and ice are predicted to affect a good section of the eastern half of America, as Canadian Arctic air is expected to dip south.

The winter storm is predicted to be one of “the biggest in recent memory,” the Daily Mail reported, with meteorologists urging people to prepare for potential power outages.

”UGH — this is not good,’ Weather Channel meteorologist Jordan Steele wrote on X. ‘ Plan now! Plan for going day(s) without power this weekend. School cancellations next week. Do not plan a road trip this weekend. This could be a situation where people get stuck on the highway.”

According to the latest update from the National Weather Service on Wednesday:

An expansive winter storm will produce swaths of heavy snow, sleet, and freezing rain from the Southern Rockies and Plains into the Mid-South starting Friday and shifting across the East Coast this weekend, possibly through Monday for New England. Extreme cold in the wake of this system will prolong snow and ice impact.

The Weather Channel, which gave it the storm the name “Fern,” reported the winter onslaught could impact more than 180 million Americans.

On Monday, ice and snow build up led to a 100-vehicle pileup — including more than 30 semi trucks — on Interstate 96 in western Michigan. Some vehicles collided in a chain reaction while others veered off onto the side and median to avoid crashing.

There were only minor injuries, according to local authorities.