SALT LAKE CITY >> A ferocious storm that crippled much of the Pacific Northwest barreled into the Rockies on Tuesday, causing whiteout conditions on one of the busiest travel days of the year.

The National Weather Service issued a blizzard warning for Utah, where Interstate 84 and Interstate 15 were temporarily shut down in northern Utah because of windy, snowy conditions that led two tractor-trailers to jackknife and block traffic. Even once the roads were reopened, visibility was still very limited there and elsewhere in the state as many commuters made their way home on snow-covered roads.

Numerous schools, governments and businesses in Utah closed hours earlier than normal Tuesday because of the storm, with state traffic officials warning the evening commute could take four times longer than usual.

Of nearly 300 flights scheduled to take off from Salt Lake City International Airport Tuesday evening, nine had been canceled, although it wasn’t immediately clear if all of those were caused by the storm.

Highway officials told holiday travelers earlier in the day to get out of town now or risk being stranded on Thanksgiving.

In the western part of Utah, empty eastbound semitrailers on Interstate 80 were being held near the Nevada line to prevent them from tipping over in the windy salt flats.

At least three deaths in Washington state have been blamed on the storm, including a man struck and killed outside his car Monday night on snowy Interstate 5 in Tacoma. Officials in Portland, Ore., also were investigating whether a man whose body was found along the Willamette River died from the cold.

Thanksgiving travel was dicey throughout the region, with many highways too dangerous to drive. In Seattle, icy roads kept airline crews from getting to the airport, and people who missed their flights because of the dangerous drive were trying to rebook on already crowded planes.

The weather service said 2.5 inches of snow fell at the airport Monday, breaking the old record for the date of 1.5 inches in 1977.

The tiny central Washington town of Waterville became a refuge when the blizzard blasted across the scattered wheat fields and sagebrush along U.S. Highway 2.

“We got sideways snow. We’ve got snow that’s going up, stuck up under things. Snow is everywhere, because it’s been so windy,” Dave Lundgren, owner of the Waterville Historic Hotel, said Tuesday. “We’re definitely going to be looking for inside things to do.”

Even cold-hardened Alaskans were complaining about the weather, with freezing rain making travel hazardous if not impossible. Fairbanks was among the hardest-hit; schools closed and most government agencies and military bases told nonessential workers to stay home.

“I don’t think the roads can get much worse,” said David Gibbs, emergency operations director for the Fairbanks North Star Borough.

Andy Haner, a weather service meteorologist in Seattle, said the storm blew down from Alaska before turning toward the Northern Rockies.

“Sometimes we call them ‘inside sliders’ because they slide down the Inside Passage from Alaska,” he said.

Citrus growers in California’s San Joaquin Valley prepared to fight off crop-damaging frost as a cold front moves into the region.

The storm reached the Salt Lake City area during the evening commute.

That’s what happened Monday night in Washington. Slick roads, blowing snow and temperatures in the mid-20s turned rush hour in Seattle and nearby cities into an hours-long crawl. Some motorists gave up after being stuck for five hours or more and returned to their offices or just left their cars at the side of the road.

Winds gusting to 65 mph made matters worse by cutting off power for tens of thousands of utility customers in Western Washington. Puget Sound Energy said it was doing all it can to restore electricity to tens of thousands of customers who lost power in the Monday night storm, but some could still be in the cold and dark on Thanksgiving.

Spokane and Eastern Washington were hit with even stronger winds and colder temperatures, staying well below zero overnight.

Tuesday dawned bright, sunny and cold over much of the state as crews hurried to plow and deice roads. Most schools closed, including the University of Washington’s three campuses.

Annie Wicken, an employee at a Seattle supermarket, said her boss practically begged her to make the hours-long, multi-bus journey to work.

“I hope people will still try to shop and get their Thanksgiving stuff,” she said while waiting at a bus stop.

Emergency shelters opened throughout the region to warm the homeless. In Olympia, the Volunteer Center of Lewis, Mason, and Thurston Counties scrambled to find people with four-wheel-drive vehicles to deliver more than 400 Thanksgiving meals to homebound seniors.

“We feel like these people get shortchanged enough in life. We’re bringing them a meal no matter what happens,” said the center’s Emma Margraf.

Two people were killed Monday when their car slid on a snowy road at Cowiche near Yakima and collided with another car, the Washington State Patrol said. Another man died when he was struck outside his car Monday night on snowy Interstate 5 in Tacoma.

The patrol Tuesday launched a plane equipped with a heat-seeking camera to look for stranded motorists from Seattle south to Olympia. It said that in the 24 hours ending at 10 a.m., troopers had responded to 1,557 collisions and 1,274 disabled motorists statewide.

Much of Northwest will get a cold but brief break to dig out and maybe brave travel for the Thanksgiving holiday before more snow that could arrive by Wednesday night.