MINNEAPOLIS (AP) - The heaviest snowstorm to hit the region in two winters dumped heavy snow across a broad belt of Minnesota including the Twin Cities area Sunday, as well as parts of western Wisconsin.
By Sunday evening, dozens of school districts across Minnesota and western Wisconsin had decided to cancel Monday classes or delay their start times due to the storm.
Forecasters said up to 15 inches of snow were possible in the Twin Cities by Sunday night. The slow-moving storm caused difficult driving and scores of mostly minor traffic accidents across much of Minnesota, highway closures in eastern South Dakota and southwestern Minnesota, and flight cancellations and delays at Minneapolis-St. Paul International Airport.
The Twin Cities' heaviest snowfall last winter was 4.2 inches on Dec. 3. The heaviest snows of the winter of 2010-11 were 11.8 inches on Feb. 20, 2011, and 16.3 inches on Dec. 11, 2010.
That last storm caused the Metrodome to collapse -- forcing the Vikings to play the final two games of the season elsewhere. The project to restore the inflatable roof cost $22.7 million, and officials there weren't taking chances on a repeat Sunday.
Steve Maki, director of facilities for the Metropolitan Sports Facilities Authority, said they cranked up the heat after Sunday's Vikings-Bears game and planned to keep it that way until the storm passed. He said everything was going well.
"What we don't want to happen is 21 inches in eight hours," Maki said. "We can handle it over 15-16 hours but eight hours gets a little tough sometimes."
Sportswriters who complained about the oppressive postgame heat up in the press box could have had a pretty nice sauna if they splashed some water on the rocks, Maki said jokingly.
The Metrodome looked only about three-quarters full at kickoff for the sold-out game, and fans streamed in late, with beads of melting snow apparent on everyone's jackets.
A blizzard warning was out for much of eastern South Dakota and southwestern Minnesota, while a winter storm warning was out for much of central and eastern Minnesota and western Wisconsin.
The National Weather Service reported 17.3 inches at Sacred Heart and 15.5 inches at Granite Falls in southwestern Minnesota and more than 8 inches in Aberdeen, S.D. Reports of 9 to 15 inches were common across the Twin Cities area by Sunday night. Rochester's 292-day streak of days without at least an inch of snow fell around 6 a.m. Sunday when its airport recorded 1.1 inches.
The Minnesota Department of Transportation reported difficult driving conditions across much of the southern two-thirds of the state, with no travel advised and several highways closed in west-central Minnesota and southwestern Minnesota.
MnDOT pulled its plows off the roads in the Granite Falls, Madison, Marshall and Montevideo areas. The plows are scheduled to return around midnight, depending on whether the wind dies down, according to spokesman T.J Melcher.
"They want to get the plows out there as soon as they can to start working on the roads, but again it has to be a safety issue," he said. "So it all comes down to that visibility and how well they're going to be able to see where they're at on the roads."
The Minnesota State Patrol reported nearly 600 crashes statewide from Saturday night through Sunday afternoon, with more than 60 involving injuries and one fatality. Lt. Eric Roeske also reported more than 960 spinouts or vehicles off the road.
Minneapolis, St. Paul, several suburban communities and St. Cloud declared snow emergencies, meaning parking restrictions will be in effect until the streets are plowed.
Around 150 flights at Minneapolis-St. Paul International Airport were canceled due to the storm, airport spokesman Pat Hogan said, but he said crews were able to keep at least one runway open. Hogan added airport officials hope Monday's flight schedule will be close to normal.
"One of the biggest unknowns is the wind -- the wind is supposed to pick up tonight, and that could create some visibility issues for us," said Hogan. "So we're waiting to see what happens with that, but if all goes well, we should be in pretty good shape."
Delta Air Lines, the airport's main carrier, said travelers through the Twin Cities and Duluth could rebook their flights without charge. The Federal Aviation Administration said the snow delayed some flights by an average of about 90 minutes.
In South Dakota, officials closed Interstate 90 between Chamberlain and Sioux Falls and Intestate 29 from Sioux Falls to Sisseton because of blizzard conditions. Greg Fuller, director of operations for the South Dakota Department of Transportation, said travel would "continue to be a challenge, and patience is part of making safe choices."
MPR's Rupa Shenoy contributed to this report