EF3 tornado in Red Lake County, Minnesota

This tornado began in Polk County, about 4 miles south-southwest of Mentor at 615 PM CDT. The tornado tracked into Red Lake County and continued an additional 6 miles to roughly 4 miles east-northeast of Terrebonne. The tornado sheared trees and blew down farm buildings near the Polk County line and lofted debris from Mentor well past the community of Plummer. The total track length was about 15 miles and peak winds were estimated at 145 mph.

Conditions were ripe by the afternoon of the 17th for a major severe weather outbreak. A surface low had moved into east central North Dakota with an occluded front extending to the southeast. Warm and humid air was in place ahead of the front, with a much drier airmass pushing in behind it. The 500mb low was located over northwest North Dakota with a nice southwest to northeast upper jet pushing into eastern North Dakota. Two lines of convection formed by late afternoon, one from Roseau County down toward Eastern Otter Tail County and the other over east central North Dakota. Nearly all the cells that formed took on a classic hook shape with rotation very evident on radar imagery. Multiple tornado warnings were issued before the event wound down by mid evening. The strongest tornadoes were determined to be EF4 tornadoes, two in west central Minnesota and one in northeast North Dakota.