The metro area is under a winter storm warning from this morning until 6 a.m. Sunday, with the possibility of 10-plus inches of snow by Sunday.
At 11 a.m., about 1 inch of snow was reported in Chanhassen.
The forecast calls for up to 8 inches of snow by midnight tonight, with sleet possible in the afternoon.
After midnight, there is a possibility of 1-2 more inches of snow, and a mix of snow and sleet is likely in the Twin Cities area.
The snow began falling this morning across a large part of western Minnesota and quickly spread across the rest of the state. It was forecast to become heavy as the day went by, with accumulations of 6 inches in many areas to as much as 16 inches in some parts of east-central and northeastern Minnesota, the National Weather Service said.
The Minnesota Department of Transportation reported difficult driving conditions by midday across many parts of the state, stretching from south to north and west to east, including the Twin Cities. Interstate 94 between the downtowns of Minneapolis and St. Paul was moving very slowly, with at least one crash in each direction.
The snow was mixing with sleet along the Interstate 90 corridor across southern Minnesota. Visibilities were down to a quarter mile in some areas due to winds gusting in the 20 mph range.
By midday, snowfall amounts between 1 inches and 3 inches were common, including the Mankato, Faribault and Twin Cities areas.
Less snow was expected across most of extreme northern Minnesota, where a snow advisory was out from the Grand Forks area to International Falls and Ely, and 3 inches to 8 inches were forecast.
Highs temperatures were forecast to range from the teens in the far north and through the 20s in central and southern Minnesota.
The Federal Aviation Administration reporting no major weather delays at Minneapolis-St. Paul International Airport by midday, though the storm had prompted the closure of the Des Moines International Airport for several hours after a United Airlines plane slid off a taxiway, and the FAA said delays for incoming traffic to Chicago's O'Hare International Airport were averaging over an hour.
Northwest Airlines said it would allow passengers planning to fly this weekend to rebook for a different date without penalty. The change applied to passengers flying to, from, or through Minnesota, Wisconsin, or Michigan on Saturday or Sunday. Passengers can rebook their travel for Nov. 30 to Dec. 4.
The Weather Service posted winter storm and ice warnings across parts of Nebraska, Iowa, Minnesota, Wisconsin, the eastern Dakotas and northern Michigan, although some warnings were lifted by midday. Much of Iowa was hit with snow, sleet and freezing rain.
Officials decided to close Des Moines International Airport after a United Airlines plane slid off a taxiway as it was heading to a runway to take off on a flight to Chicago's O'Hare, said airport spokesman Roy Criss.
Criss said the 44 passengers on board were taken back to the terminal by bus. No one was injured.
As of late morning, 28 flights were canceled, but airport officials hoped to reopen by mid-afternoon.
"That's going to be a moving target," Criss said.
Jeff Kovick, a United spokesman, said the company is investigating the runway accident.
"We're focusing on trying to get our customers to their destinations as safely and as quickly as possible," Kovick said.
Heavy accumulations of ice coated power lines and blacked out more than 2,000 customers scattered around Iowa, said Allan Urlis, a spokesman for MidAmerican Energy.
The Iowa Department of Transportation advised people not to travel on highways in central and south-central parts of the state.
Numerous accidents were reported, said Transportation Department spokeswoman Dena Gray-Fisher.
One southbound lane of Interstate 35 in southern Iowa had to be closed after a tractor-trailer rig overturned across the median, and Gray-Fisher said it could be hours before cargo could be unloaded and the truck removed. State Patrol dispatchers said the driver was injured but the severity wasn't known.
Snow and blowing snow with wind of 20 to 25 mph reduced visibility in southeastern South Dakota and brought cancellations of regular weekend activities such as YMCA basketball, church practices, high school athletics and community events. One Sioux Falls television station had posted 43 event cancellations and postponements on its Web site by noon.