Tornado Forms Over Chicago on Tuesday

CHICAGO, IL — A "landspout" tornado formed in Chicago Tuesday afternoon, Aug. 9, just before 4 p.m., according to the National Weather Service, the first to form in the city in a decade.

Melanie Harnacke, the FAA contract observer at Midway Airport, photographed the tornado and tracked the rare urban phenomenon from 3:48 p.m. until 3:58 p.m. The tornado formed on the Southwest Side, near Cermak and West Ogden.

The last city tornado was recorded on Sept. 22, 2006, a brief F-0 tornado on the campus of Loyola University.

Illinois Storm Chasers, a weather group based in Plainfield, commented on Facebook:

Landspouts are basically (non scientifically) a dust devil on steroids. They are non supercell tornadoes and occur along a thermal or vorticity boundary under cumulus clouds. To see them around here is rare, to see it in the middle of the metro is mind blowing. They can produce damage and are not harmless, but are more often than not undetected in these circumstances.

photo by Melanie Harnacke, Federal Aviation Administration