Minnesota apparently recorded its strongest blast of wind ever Thursday morning, with an emphasis on the word "recorded."
Winds measured at 121 miles per hour near Donaldson over a 10-minute period damaged grain bins, homes and trees in and around the small city in far northwestern Minnesota. A state transportation department device made the readings.
Many tornadoes carry winds stronger than that, but those winds are inferred from surveys of damage after the twisters blow through. The tornado that hit Wadena, Minn., in 2010, for instance, was considered to carry winds of 170 mph, but that is regarded by the National Weather Service as an estimate, not an actual measurement.
The previous Minnesota record for a measured wind speed was 110 mph, in a combination of straight-line winds and tornadoes that hit Minneapolis Aug. 20, 1904, said assistant Minnesota DNR climatologist Pete Boulay. Wind-measuring devices in stronger storms have typically been blown away, shattered or otherwise rendered useless.
"We've obviously had wind speeds greater than that in the state, but how do you measure them?" Boulay said. "We obviously now have an instrument that measured it."
Weather officials will examine the MnDOT device, which is located a mile west of Donaldson on Hwy. 11, before certifying the wind speed as accurate.
Hurricane Irene carried sustained winds of 85 mph when it made its U.S. landfall last Saturday. Winds of 121 mph would be equivalent to a Category 3 hurricane.
The winds that hit Donaldson just after 3 a.m. Thursday were part of a line of storms that cut across that corner of Minnesota and moved on into Canada. Other blasts from the storm were measured at 85 mph. The winds slowed after they moved out of Marshall County, said Dave Kellenbenz, senior meteorologist for the Grand Forks office of the National Weather Service.
Grand Forks received more than 1.5 inches of rain from the storms; 2.64 inches fell north of Crookston.
Bill McAuliffe • 612-673-7646