MINNEAPOLIS (WCCO) — National Weather Service survey teams have ranked the deadly tornado that roared through Otter Tail and Grant counties earlier this week as an EF-4.

According to the NWS, the tornado grew out of a rapidly developing supercell thunderstorm just after 5 p.m. Wednesday. The tornado first touched down in far northern Grant County — west of Ashby — as a weak tornado, but “quickly intensified into a strong to violent tornado” as it made its way into southern Otter Tail County on Interstate 94.

The tornado seen in Otter Tail County. (credit: Alissa Wilbur)

“The tornado intensified to a strong tornado (EF-2 to EF-3) as it moved northeastward through southwestern St. Olaf Township and crossed Beebe Lake,” the NWS said in the review.

National weather officials say the tornado likely reached maximum EF-4 intensity after it crossed Highway 82 and destroyed a machine shop and yard.

The Otter Tail County Sheriff’s Office says one person was killed and two others injured as tornado neared Dalton. Three farmsteads were hit, and one of those farmhouses was flattened, said meteorologist Vince Godon with the National Weather Service in Grand Forks, North Dakota.

MORE: Read the full NWS report

The tornado is estimated to have had peak wind speeds of 170 miles per hour and went nine miles before roping out east of Dalton. The “long lived” tornado lasted 31 minutes, according to the NWS.

More tornado information (credit: NWS)

The same storm may have produced one, or multiple, brief tornadoes along its path.

It’s the strongest tornado confirmed in Minnesota since 2010. Notably, the previous EF-4 occurred one county to the west in Wilkin County.

The NWS says the ranking of Wednesday’s tornado is preliminary as storm events are not final until published in Storm Data, which will take several months.

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