MINNEAPOLIS (AP) -- Hospital executive Robert Stevens donned four layers of long underwear, heavy boots and a down coat before climbing on the roof of a Minnesota coffee shop to raise money for his daughter's school.
He vowed not to come down until he had raised $100,000, but after reaching the halfway mark Saturday morning, he said he hoped the rest of the money would come fast. He didn't look forward to spending another night out in the blizzard that was sweeping through the Midwest.
"I think I've crossed the line into insanity," he told The Associated Press.
The storm formed in the Rocky Mountains on Friday and then swept into northern Nebraska and Iowa overnight. By Saturday morning, heavy snow and strong winds had created blizzard conditions across eastern South Dakota, northwest Iowa and southwest Minnesota, and the storm was moving east into Minnesota's Twin Cities and western Wisconsin.
Stevens camped Friday night on the roof of the Dunn Brothers coffee shop in the Minneapolis suburb of Excelsior. The president and chief executive of Ridgeview Medical Center in nearby Waconia, he was raising money for the private Spring Hill School, where his daughter attends eighth grade.
He slept inside a tent surrounded by hay bales, swaddled in a double-insulated sleeping bag as he listened to the winds whip off Lake Minnetonka a block away.
Stevens said the blizzard may turn out to be fortunate since it's bringing more attention to his fundraising goal. But he also questioned whether, if he doesn't get there by nightfall, he could bear another night on the roof.
"Right now I'm thinking I can do it," he said. "But nature might get the upper hand later on tonight."
With near whiteout conditions in many areas, Minnesota transportation officials closed westbound Interstate 90 from Albert Lea to the South Dakota border, pulled plows off roads in the southern part of the state and told drivers to stay home.
"With this type of a storm, it's a blanket approach, because it's a visibility issue," Minnesota Department of Transportation spokeswoman Rebecca Arndt said.
Portions of Interstates 29 and 76 were closed in Iowa and South Dakota because of blowing snow and related crashes.
Between 8 and 18 inches of snow were expected in Minnesota, with the heaviest snowfall stretching from near Hutchinson and Mankato to the Twin Cities. Heavy snow also was falling in northern Iowa, where up to 10 inches were expected, and eastern South Dakota, where 5 to 8 inches were forecast.
About eight inches had fallen by lunchtime in the Seward neighborhood of southeast Minneapolis. Lisa McGrath, an artist, was shoveling her front walk -- even though she'd likely have to be out there doing it again in a few hours.
"It's good exercise -- the only exercise I'm going to get today," McGrath said as she hoisted the shovel.
Tyler Hoverson, 18, was part of a six-person crew clearing snow at a Minneapolis-area strip mall early Saturday morning. He had been at work since 3 a.m. and, with snowfall expected to continue all day, he predicted he'd be there until 2 a.m. Sunday.
""It's discouraging," he said, his eyebrows frosty with snow. "Feels kind of unproductive."
The snow was expected to be followed by dangerous cold. A wind chill advisory covered most of North Dakota on Saturday morning. North winds of 15 miles per hour or more combined with air temperatures at or below zero to drop wind chill readings to 20 below zero, the National Weather Service said.
The arctic air was expected to spread east behind the storm, dropping temperatures below zero throughout the Dakotas and in parts of Iowa, Minnesota and Wisconsin by Sunday night.
There was a bustling lunch crowd Saturday in the Birchwood Café in Minneapolis, which stayed open for business. Collette Dennis, a baker there, was back inside after she and co-workers spent 20 futile minutes trying to free her parked car from a snowdrift. Dennis still hoped to figure out a way to get home to the suburb of Roseville, about 12 miles away -- but she also was prepared to stay put.
The café had no cots, Dennis said, "but we have multiple bags of flour I could sleep on. And I guess at least I won't go hungry."
Associated Press writers Dirk Lammers in Sioux Falls, S.D., and Jeff Baenen in Plymouth, Minn., contributed to this report.