Detroit's first tornado since 1997 fits a pattern scientists expect to keep growing

The National Weather Service office in Detroit/Pontiac rated the storm an EF-2 in its post-storm survey, with estimated peak winds of 115 mph. The tornado touched down at 4:14 p.m. on September 3 about two miles northeast of Comerica Park and lifted four minutes later, at 4:18 p.m.

In that short window it carved a path 3.5 miles long and up to half a mile wide, the survey found. The survey logged one injury.

It was Detroit's first tornado since 1997, as first reported by BridgeDetroit.

The Detroit tornado was one of three the weather service confirmed over two days, alongside EF-0 touchdowns in Marysville on September 2 and Lincoln Park on September 3. Earlier that afternoon, the University of Michigan issued a campus emergency alert for a tornado warning in Washtenaw County, telling students to move to the lowest level away from windows until 4:15 p.m.

The city's storm capped an unusually active stretch. Michigan's 28th tornado of the year struck Detroit on Thursday, according to BridgeDetroit, well above the roughly 15 the state averages in a year. Last year there were 33.

Richard Rood, a professor emeritus at the University of Michigan, told BridgeDetroit that "the background conditions that are conducive to the formation of severe storms and the formation of tornadoes are becoming more common." The trend he pointed to is "the increase of water vapor in the atmosphere."

Trent Frey, a National Weather Service meteorologist, told BridgeDetroit that "August was relatively quiet across the area, so this was kind of a return to a stormy, summery kind of atmosphere and pattern."