The winter storm that has coated the Pacific Northwest with a thick blanket of ice was sweeping east on Thursday, threatening more heavy snow across a huge part of the country from the Rocky Mountains through the Great Lakes region.
The storm was expected to race across the upper Plains on Thursday night and Friday and wallop the Midwest and the Great Lakes region by Saturday morning, forecasters said.
The storm slicked the Willamette Valley of Oregon with an inch of solid ice Wednesday, and it could leave behind 2 feet of snow in Yosemite National Park in Nevada and parts of Wyoming and Utah.
More from NBC News:
What's all of this talk about the polar vortex?
Annual Arctic report card details a year of extremes
5 ways to stay safe when it's dangerously cold
One person was dead in Oregon — an unidentified man in his late 50s who was found covered in a layer of ice and snow in his driveway Wednesday night in Albany, the Linn County Sheriff's Office said.
And the bombardment won't let up on its way east. Winter storm warnings were in effect Thursday from the Sierra Nevada in California to the Rocky Mountains, east to the Upper Midwest and north as far as Wisconsin, where Green Bay and Madison could both get more than a foot of snow by the weekend, forecasters said.
Three plow trucks ran off the road and got stuck in the snow Thursday in Chippewa County, Michigan, the county Road Commission said. Rescue vehicles were needed to extract the trucks, it said.
By Saturday morning, the storm is forecast to slam the eastern third of the country, especially parts of Michigan, Ohio, Pennsylvania and New York around the Great Lakes.
That's an area where conditions are already a mess — lake-effect snow up to 20 inches and temperatures as much as 30 degrees below normal have caused chaos on the roads and killed a New York boy who was buried in his snow fort.
Almost 60 vehicles piled up in a mammoth crash Thursday morning on Interstate 80 in Falls Creek, Pennsylvania, the state Transportation Department said. Authorities told NBC station WJAC of Johnstownthat only three minor injuries were reported, but the freeway remained closed for 7 miles eastbound well into Thursday afternoon, the Transportation Department said.
Two boys, ages 12 and 13, were buried in a snow bank Tuesday in Greenwich, New York. Joshua Demarest, 13, and Tyler Day, 12, were both alive when they were pulled from the snow after a massive rescue operation, but Joshua was later pronounced dead at Saratoga Hospital, Cambridge-Greenwich Police Chief George Bell said.
Tyler was recovering at home from hypothermia.
The boys were carving out a fort in a 10-foot bank of snow when a public works truck — its driver unaware that they were there — dumped a load of cleared snow on top of them, Bell said.
"This is a true tragedy," Bell said. "Tyler tells his dad and my officers in the emergency room ... that he heard what he believed was beeping sounds, and the next thing you know, it went black."
Near-whiteout conditions are forecast around Lake Erie as the western storm moves in later, the National Weather Service said. Authorities on Wednesday night closed the Buffalo Skyway, a critical segment of New York State Route 5 through the city, which was under a blizzard warning through early Friday.
"These lake-effect snow bands, the snow is so ridiculously heavy that the ground gets slippery under them really, really, really fast, and visibility goes down to zero," said Ari Sarsalari, a meteorologist for The Weather Channel.
The snow did help out police in Michigan, however.
Two men, ages 17 and 19, were arrested Thursday morning on suspicion of trying to rob a gun store in Roseville, about 10 miles northeast of Detroit.
The men, who haven't been identified, hooked a tow strap to the store's security bars and tried to pull them off with their pickup truck — which promptly got stuck in the snow, NBC station WDIV of Detroit reported.
The men fled on foot, but they were found and arrested 3 miles away, police said.
They weren't hard to find. Cops simply followed their footprints in the snow.