MOORHEAD — An early fall snowstorm plunged residents of northern Minnesota into winter-like conditions Thursday, slowing travel and causing power outages while smothering wildfires in the northwest.

The National Weather Service issued a winter storm warning for northwestern Minnesota, where more than a foot of snow was expected to fall through Friday.

Some schools canceled classes, including Thief River Falls and Stephen-Argyle, but students from other schools were digging out winter coats, boots and hats and bundling up for the trip to school in blustery conditions.

Wet, heavy snow pulled down power lines and temporarily cut service to 6,500 Xcel Energy customers in the Moorhead area early Thursday. Service was restored by midmorning, the utility said. The Forum building in Fargo, N.D., was among those that lost power, temporarily trapping two employees in an elevator.

Snow accumulations from 6 to 12 inches are expected across the northern Red River Valley into northwestern Minnesota by Thursday night, according to the weather service. Wind gusts of 45 mph or higher could produce blizzard-like conditions and make travel hazardous.

On Minnesota’s eastern border, residents of Duluth who basked in 70-degree weather on Wednesday turned on the furnace for temperatures in the 40s and 50s the following day. About 4 to 6 inches of snow was in the forecast north of a line from Bemidji to Ely through Friday.

The National Weather Service said an estimated 14 inches of snow had fallen 10 miles north-northwest of Badger as of 3 p.m. Thursday. Roseau reported 7 inches of snow, Karlstad 6 inches, Stephen 5 inches and Hallock 4 inches.

Rain turning to snow dampened wildfires in northwestern Minnesota, but not before they consumed more than 56 square miles of woods and grassland this week. Eleven homes and two dozen other structures were destroyed in the Karlstad area due to wildfires fueled by dry and windy conditions.

“From a protection standpoint, it’s a blanket of security around structures that didn’t burn near structures that did,” Karlstad Fire Chief Jeremy Folland said. “It’s back to business as usual, so we’re not on active alert.”

Visiting fire and emergency crews, including those from federal and state agencies that responded to the weekend fires, are beginning to demobilize, Folland said.