Kevin Eastvold, of Mason City, Iowa, pushes through the snow at the end of his driveway Sunday. Parts of the state remained under a blizzard warning Sunday.

CHICAGO — A powerful, gusty storm dumped mounds of snow across the upper Midwest on Sunday, closing major highways in several states, canceling more than 1,600 flights in Chicago and collapsing the roof of the Minnesota Vikings’ stadium.

At least four weather-related deaths were reported as the storm system dropped nearly 2 feet of snow in parts of Minnesota and marched east. A blizzard warning was in effect Sunday for parts of eastern Iowa, southeastern Wisconsin, northwestern Illinois and northern Michigan, according to the National Weather Service. Surrounding areas, including Chicago, were under winter storm warnings. Much of Iowa was under a wind-chill advisory.

The wintry weather, with blowing snow that severely limited visibility, wreaked havoc on air and road travel. In the Chicago area, wind gusts of up to 50 mph, temperatures in the teens and wind chills well below zero were expected, along with up to 8 inches of snow.

At least 1,375 flights were canceled at O’Hare International Air- port, and more than 300 were canceled at Midway International Airport, Chicago Department of Aviation spokeswoman Karen Pride said. Both airports expected more cancellations and reported significant delays.

Major highways in several states were closed due to poor driving conditions and accidents.

Tod Pritchard of Wisconsin Emergency Management warned that Sunday afternoon would be especially difficult because temperatures were falling and at a certain point, road salt would no longer work. The storm had already dropped up to 18 inches of snow in parts of Wisconsin, he said, and light snow continued Sunday.

Record rains raise flood threat on Northwest rivers

SEATTLE — Record rainfall in the Pacific Northwest triggered mudslides and threatened to cause severe flooding of some western Washington rivers Sunday.

Although the rain had eased in much of southwest Washington and northwest Oregon, including Portland, downpours continued from Seattle north, swelling rivers and threatening some small towns. The rain was expected to lessen Sunday evening, with the worst of the flood danger over by early today.

Still, flood watches or warnings remained in effect for the region, and forecasters said storms could dump 6 inches or more of rain in the Cascade Range and Olympic Mountains.

“We’re looking at the wettest storm system we’ve had in almost two years,” said National Weather Service meteorologist Kirby Cook in Seattle.

Seattle-Tacoma International Airport set a rainfall record for the date of 1.42 inches, breaking the old mark for Dec. 11 of 1.32 inches set in 1955. Quillayute on the Pacific Coast also had a record for the date, 2.17 inches. The old record was 1.64 inches, set in 2002.

Cook described the storm system as a “plume of very moist, warm Pacific air.”

National Weather Service meteorologist Dave Elson in Portland said coastal Oregon rivers and tributaries of the Willamette River could rise out of their banks, but said the flood threat wasn’t as severe as in Washington.

Portland city officials said an overnight break from the rain allowed most flooded intersections to drain.

— The Associated Press