Slippery roads during a light snowfall Wednesday night and Thursday morning were just a road-greasing warm-up for what is likely to be a snowstorm of more consequence arriving this weekend.

A broad swath of southern Minnesota, from Marshall in the west to Red Wing in the east, is under a winter storm watch that is expected to bring 4 to 8 inches of snow to the area Saturday, according to the National Weather Service in Chanhassen.

The Twin Cities metro area lies north of the official watch area, but is still expected to get 2 to 4 inches of snow Saturday.

Overnight Wednesday, scores of crashes were reported on metro roads, and Thursday morning’s rush hour consisted of a long crawl until roads were cleared and salted. All told, 2.3 inches of snow was recorded at the Minneapolis-St. Paul International Airport, according to the Weather Service.

Among Thursday morning’s crashes were one involving a jackknifed semitrailer truck that blocked all the northbound lanes of Interstate 35W at Nicollet Avenue in Richfield for about 90 minutes. The truck slammed into the concrete median and knocked a piece of the barrier loose shortly before 5 a.m., the Minnesota Department of Transportation said.

Still, Thursday brought fewer crashes than Wednesday, when the State Patrol responded to 379 wrecks statewide between noon and 9:45 p.m. The patrol also responded to 95 vehicle spinouts and seven jackknifed semitrailer trucks during the same time period.

MnDOT deployed scores of plows around the metro to manage the overnight and morning snow. Hennepin County sent out 71 trucks to spread anti-icing materials and clear snow and ice from county roads.

Other snow totals included 2.1 inches at the Weather Service’s office in Chanhassen, 2 inches in Watertown, 1.9 inches in Fridley and Mendota Heights, 1.4 inches in Jordan, 1 inch in Osseo and 0.9 inches in Eau Claire, Wis.

Friday’s weather is expected to be quiet in the metro, with clouds and a high near 35.

Saturday’s precipitation will start as a mix of snow and freezing rain Saturday morning and transition to heavy snow accompanied by high winds by noon.

“Travel could be very difficult, especially along I-90 and along I-35 between the Twin Cities and the Iowa border,” the Weather Service said. “Patchy blowing snow could significantly reduce visibility.”