Gov. Tim Walz issued an emergency executive order to activate the National Guard on Tuesday and officials urged Minnesotans to prepare — but not panic — as a potentially historic snowstorm barreled into the state.

Cities declared snow emergencies, schools were shifting to remote learning and airlines were scrapping flights at the Minneapolis-St. Paul International Airport ahead of the storm the National Weather Service labeled "extreme."

With 16 to 22 inches of snow predicted to fall from Tuesday night to Thursday afternoon and winter storm and blizzard warnings in effect across much of the state, authorities advised Minnesotans to stay home.

"This is not the time to tempt fate," State Patrol Col. Matt Langer said during a Minnesota Department of Public Safety news conference. "Think twice before you drive."

The storm will arrive in two parts, with the main event expected Wednesday night into Thursday, the Weather Service said.

Star Tribune
Video (01:35) The latest forecast looking at the record-setting snowstorm taking aim at Minnesota.

Warm air flowing north and cold air dropping out of Canada is converging over Minnesota, putting the Twin Cities in "a prime spot" for a major snowfall, said Tyler Hasenstein, a meteorologist with the National Weather Service's Chanhassen office.

"The storm will grab your attention," said Kevin Reed of the state's Homeland Security and Emergency Management division. "Be prepared, but don't panic."

Snow began falling across western Minnesota before noon Tuesday and moved into the metro area just before 3 p.m. Winds gusting between 35 and 50 mph were expected to produce whiteout conditions and create drifts several feet high, the Weather Service said.

"This could be a pretty serious storm, so prepare accordingly, be ready for it," Walz said. "The good news is Minnesota has all the capabilities in terms of equipment, and Blizzo is on the road, so that's good."

Blizzo was one of the winning names in the Minnesota Department of Transportation's recent "Name a Snowplow" contest. The agency will deploy the plow named after the musical artist — and every other plow it has — as the storm moves in, spokesman Jake Loesch said.

"It's all hands on deck," he said, noting there will be 200 plows operating around the clock in the metro area and hundreds of others across the state.

In addition to keeping vehicles full of gas, State Fire Marshal Jim Smith reminded property owners to continually clear pathways to their homes and businesses as snow accumulates.

"That is the lifeline to get out of your house," he said.

He also reminded homeowners to check their smoke and carbon monoxide detectors.

The high winds and heavy snow could possibly down power lines, the Weather Service warned.

Minneapolis Public Schools said instruction will shift online for the rest of the week. Classes in St. Paul will be conducted remotely Wednesday and Thursday. Both districts said after-school activities were canceled.

Eden Prairie, Edina, St. Cloud, Osseo and Rosemount-Apple Valley-Eagan were among districts that also announced students will attend class remotely Wednesday and Thursday.

Anoka-Hennepin, the state's largest district, does not have an e-learning plan, district spokesman Jim Skelly said. Classes are canceled throughout the district Wednesday and Thursday.

Federal courts in St. Paul, Minneapolis, Fergus Falls and Duluth will be closed Wednesday and Thursday but are set to reopen Friday. Court staff will work remotely, according to a statement from Rebeccah Parks, public information officer for U.S. District Court in Minnesota.

The Minnesota House and Senate are putting their work on hold after Tuesday night. Staff said they don't plan to hold meetings — either in-person or remote — until Monday. The last weather-related legislative shutdown was during the polar vortex in 2019, but only the Senate closed shop then.

Several metro-area cities declared snow emergencies starting Tuesday night, including Brooklyn Center, Brooklyn Park, Bloomington, Crystal, Eden Prairie and Mounds View.

Minneapolis and St. Paul will both declare snow emergencies starting at 9 p.m. Wednesday.

In the meantime, Minneapolis said it will open more than 1,600 spaces in city lots for people to park during the storm. St. Paul, which will call back-to-back snow emergencies, will allow residents to park for free in eight downtown ramps owned by the city starting at 5 p.m. Wednesday.

"We are bracing for what is likely to be one of the largest snowstorms in Minnesota history," St. Paul Mayor Melvin Carter said at a news conference alongside Minneapolis Mayor Jacob Frey. "We expect it to have major impacts across the Twin Cities on every aspect of life, every aspect of city operations, for the rest of this week."

Ahead of the storm, several airlines were granting travel waivers to those flying in or out of Minneapolis-St. Paul International Airport, as disruptions were likely. Delta is allowing passengers at airports in Rochester, International Falls, Hibbing, Brainerd, Bemidji and Duluth to rebook flights without change fees. Sun Country, United, American and Spirit airlines also have issued travel advisories.

By midday Tuesday, dozens of flights scheduled Tuesday and Wednesday had been canceled, airport spokesman Jeff Lea said. Sun Country had canceled 55 flights originally scheduled for Wednesday and Thursday, the airline said.

More than 115 plows, brooms and other equipment "from large to small" will be used around the clock to keep the airport operating, Lea said.

Transit agencies were running on schedule Tuesday morning, but advised passengers to subscribe to email and Twitter alerts to keep informed of service changes. The Minnesota Valley Transit Authority will have buses on standby to put into service if delays develop.

Metro Transit said buses will continue to run, but "once conditions have become too dangerous for service to continue, buses are ordered to halt at the next safe location," the agency said in a tweet.

Alerts will be sent to customers via text and email and notices are posted to the agency's website and on real-time signs.

Homeless outreach teams in Minneapolis and St. Paul were out Tuesday urging people to make use of shelters, which had beds available. Hennepin County officials emphasized that they have essentially unlimited capacity for families with children, and those in need of shelter should call 612-348-9410. Single adults can call 612-248-2350. The Youth Services Network for shelter is available at ysnmn.org.

Staff writers Briana Bierschbach, Jessie Van Berkel, Stephen Montemayor, Eder Campuzano, Katie Galioto and Dave Orrick contributed to this report.