St. Paul and Minneapolis declared snow emergencies effective 9 p.m. Monday as a winter storm pounded the state for a third day, causing hundreds of crashes and spinouts.

State Patrol Sgt. Jesse Grabow said this weekend’s storm is one of the worst he’s seen.

“Being born and raised here and working it for 20-plus years, as far as the ugliness and making travel difficult, this storm is probably a Top 10,” he said while parked on the side of Interstate 94 on Monday afternoon near Barnesville, Minn.

The State Patrol reported more than 700 crashes or spinouts and investigated a crash involving a MnDOT plow that struck a bridge in Plymouth.

The patrol responded to 310 crashes that caused 33 injuries statewide between 5 a.m. and 9:45 p.m. Monday. None resulted in serious injuries or deaths. The patrol also responded to 429 spinouts and aided 31 jackknifed semitrailer trucks, authorities said.

Grabow assisted a semitrailer truck that had been stuck in a ditch since Saturday evening. The truck, loaded with apples, was being towed, and the produce had to be transferred box-by-box to another truck.

About 5:20 p.m. Monday, a MnDOT plow truck struck a bridge on Hwy. 169 and Bass Lake Road in Plymouth, according to the patrol. The bridge did not suffer structural damage and no one was injured. The crash remains under investigation.

A winter weather advisory was in effect until midnight for most of Minnesota while a winter storm warning was in effect for counties along the North Shore of Lake Superior and the western half of Wisconsin, the National Weather Service said. The metro area was in line to receive 4 to 7 inches of snow, said Chris O’Brien, a forecaster at the National Weather Service in Chanhassen.

St. Paul’s snow emergency meant no parking on streets with signs reading “night plow route” or “night plow route this side of street,” which started Monday night and continued through Tuesday morning. All streets in downtown St. Paul were affected by the nighttime parking ban even if there is no signage.

The snow emergency rules for Minneapolis prohibited parking on either side of a snow emergency route through 8 a.m. Tuesday, or until after the street is fully plowed.

The slow-moving and fickle storm created road conditions that varied from mile to mile. At midday Monday, driving was relatively good northeast of Rochester where roads were mainly wet. But conditions changed fast as temperatures began dropping and snow moved in, said MnDOT spokesman Mike Dougherty.

To the west of Rochester, roads were partly ice- and snow-covered in places, said Rebecca Arndt, a MnDOT spokeswoman.

Early Monday afternoon, the stretch of Hwy. 60 between Madelia and Mankato was littered with crashes, including a jackknifed semi.

“It’s definitely a problem area,” Arndt said. “We were feeling pretty lucky after the weekend, with snow Up North and ice in the Twin Cities. Today, I guess it’s our turn.”

In the metro, main roads were mostly wet and slushy as snow fell.

Freezing drizzle turned to snow in the metro area during Monday’s morning commute as temperatures hovered on either side of the freezing mark. That had MnDOT doing a “delicate dance,” said spokeswoman Anne Meyer. Plows were dispatched overnight to drop chemicals to keep roads from freezing, but rain was washing some of that away. And the agency didn’t want to put down too much before the snow arrived, because plows clearing roads would scrape it away, Meyer said.

“It’s an awkward phase,” she said. “We’d like it if it were a few degrees warmer or cooler.”

In a weather oddity, Monday’s wintry mix was moving into Minnesota and the metro from the east as a low pressure system slowly moved across Wisconsin. Strong winds gusting from between 20 and 40 mph created tricky travel conditions.

Earlier, authorities briefly shut down a segment of southbound Hwy. 65 in Fridley just north of Interstate 694 on Monday morning where slick roads may have led to a serious crash in the area of Moore Lake Drive.

Elsewhere in Minnesota, authorities lifted most travel advisories that had been in effect much of Sunday. But they warned that it will take time for road conditions to improve. Motorists were advised to reduce speeds, drive according to conditions and be alert for changing road conditions.

People cooped up the past few days are getting behind the wheel and driving way too fast, Grabow of the State Patrol said, adding that even 55 mph is risky on slick roadways.

“Driving and traveling is the most dangerous thing you’re going to do,” Grabow said. “Folks forget what a huge responsibility it is to maintain control of your motor vehicle. If you can’t do that, then wait it out.”

Many places in the northwest part of the state received more than a foot of snow over the weekend. The town of Oklee, Minn., reported 17 inches, Brooks had 16 inches, and Bagley, Bemidji and Climax all recorded 13 inches, according to the National Weather Service.

Tuesday is expected to be cooler, with a high in the low 20s with sunny skies. Then mild air will return to the Twin Cities in time for the New Year. Wednesday will feature a high of 32 degrees and Thursday will be even warmer at 37 degrees, the Weather Service said.

The next chance of snow will come Thursday night into Friday, the Weather Service said.

Staff writer Chao Xiong contributed to this report.