Three tornadoes briefly touched down in northwest Minnesota on Wednesday, June 17, according to an investigation by the National Weather Service. The most damaging of the three tornadoes tore through a Roseau County farmstead shortly after 9 p.m., destroying a pole shed and causing other wind damage.
The first of the three touched down in Roseau County near Greenbush for about 2 miles after a tornado warning was issued for the area shortly before 5:30 p.m. The tornado, which NWS Grand Forks warning coordination meteorologist Gregory Gust described as a classic supercell tornado, was choked off quickly.
Multiple storms continued to hit the area diagonally from Grand Forks to Roseau County throughout the night. A second tornado warning was issued for Marshall County around 8:50 p.m. and was extended to Roseau County around 9:15 p.m. That storm produced the second tornado, which touched down about 4 miles southwest of Florian, Minn., and ended about 1 mile southeast of Florian.
Just after 9 p.m., a severe thunderstorm warning was issued for portions of Kittson, Marshall, Roseau and Lake of the Woods counties as a squall line containing supercells moved across the area. Gust estimated that the area from Haug, Minn., to Pinecreek, Minn., received winds reaching speeds of 90 mph, resulting in significant damage to the area, including a pole shed which was peeled open and blown away.
Because the path of the shed's debris was consistent with the direction of the winds, Gust said he doesn't suspect the damage was the result of a tornado. That wasn't the case on a nearby farmstead though, he said.
Around 9:10 p.m., Gust said one resident watched a funnel cloud drop down as it came toward his property 2 miles west of Pinecreek. The tornado touched down and traveled through his property, blowing apart his pole shed and scattering debris up to a half mile away. The northward debris path did not follow the eastward direction of the wind, a telltale sign of a tornado, Gust said.
Unlike the tornadic supercells, which Gust said are slightly more common for the area, the third tornado was caused by a quasi-linear storm. He said tornadoes can be more difficult to spot from the ground in quasi-linear storms than in the distinctive supercell storms.
That particular storm had a severe thunderstorm warning rather than a tornado warning because the greatest threat from quasi-linear storms is the widespread wind damage, Gust said. For example, the same storm caused a steel grain bin to cave in, causing its roof to pop off in Kittson County. The storm's strong winds rather than a tornado is expected to be the culprit.
He added that this is just the beginning of tornado season for the Northern Plains - tornadoes are expected to be most active in June, July and August in northern North Dakota and Minnesota.
Despite more frequent reports and warnings of tornadoes in the area, Gust said tornadoes in the area aren't becoming more common. Instead, radar has gotten better at detecting them, and social media has given a wider range of people the ability to report them when they see them.
He added that, when the state was more rural and the population more spread out, strong tornadoes were frequently less devastating and caused less insurable damage.
"But there have been strong tornadoes across the area going back for as long as it has been settled," Gust said.