Patriots head coach Mike Vrabel says he can’t control when the team will return to Foxboro after Sunday’s AFC Championship in Denver, as a massive winter storm is forecast to slam New England and a majority of the country.

“I think we have multiple plans of what could go based on the weather — something that they’re familiar with here,” Vrabel told reporters on Friday about when the Patriots would be arriving home following the title game.

“I mean, there’s things I can control,” New England’s first-year head coach added. “Players staying off their phone and the weather, two things that I can’t control.”

A Winter Storm Warning is in effect in Massachusetts from 7 a.m. Sunday through 8 p.m. Monday, with the heaviest snowfall forecasted Sunday afternoon through midnight. Forecasts predict 12 to 18 inches, with the southeastern region of the state, including Foxboro, predicted to receive up to 12 inches.

The Patriots-Broncos title matchup is set for a 3 p.m. kickoff at Empower Field at Mile High in Denver. The game was top of mind for Massachusetts and Boston officials, who briefed the media on storm preparations on Saturday.

Boston Police Commissioner Michael Cox wrote a letter to city colleges and universities on Friday, urging students to remain indoors.

“Obviously, everyone wants to watch the game and root for the team they find their favorite,” Cox said at a news conference on Saturday. “It’s pretty obvious who will win, though, but the issue for them is that we celebrate appropriately and responsibly.”

Mayor Michelle Wu added, “Get your snacks for the Patriots game now, before it gets toward when the snow starts falling … so you can stay inside and stay home after the game is done, and we are all celebrating.”

Beyond Massachusetts, forecasters say over half the U.S. population could be affected by snow, ice or bitter cold as the major winter storm sweeps across the country. The Patriots traveled to Denver on Saturday as fans sent the team off in the bitter cold, with players and coaches boarding buses at Gillette Stadium in the early afternoon.

Nancy Burnham, a physics professor at Worcester Polytechnic Institute, told the Herald that she would have thought that the Patriots would have flown out much earlier to acclimate to the altitude, given how Denver is exactly a mile above sea level, or 5,280 feet.

“If you don’t have the oxygen, your muscles can’t do their thing,” Burnham said, “so it’s a concern.”

Because of a snowstorm that hit New England during the Divisional Round last Sunday, the Texans had trouble flying back to Houston. The team didn’t land in their home city until just after 8 a.m. Monday morning — more than 12 hours after the Patriots ended their season in Foxboro.