Blizzard conditions made travel hazardous Sunday across the northern Plains as officials closed major highways and urged people to stay home.

The National Weather Service estimated as much as 13 inches of snow had fallen at Williston and about a foot in Bismarck, and strong wind whipped the powdery snow and cut visibility.

Bismarck's temperature at 1 p.m. was minus 8 degrees, but the wind made it feel more like minus 35, Weather Service meteorologist Patrick Ayd said.

"You need two parkas," he said.

In Fargo, the Cass County sheriff's office said visibility was down to zero with heavy drifting on the roads.

North Dakota officials said a 200-mile stretch of Interstate 94 was closed from Jamestown to Alexandria, Minn., along with the entire stretch of I-29 in the state from the South Dakota border to Canada. A section of I-29 north of Brookings, S.D., also was closed late Sunday morning.

The South Dakota Highway Patrol said that Interstate 90 reopened after being closed in the morning but that the dangerous wind chills, snow drifts and areas of zero visibility remained. Secondary roads in some other parts of the state were under a "no travel" advisory.

Many North Dakotans had been preparing for the storm since Wednesday.

"We had a lot of cancellations for the weekend. People were watching the weather," said Dee Martell, manager of a Ramada Limited Suites motel off I-94 in Bismarck.

Wind gusted up to 40 mph across most of South Dakota, and as much as 8 inches of snow fell in Roscoe.

The Minnesota Transportation Department's Web site said blowing snow produced difficult driving conditions for most areas west and north of the Twin Cities. Many roads in western Minnesota closed.