Microburst in Northern Illinois

April 25, 2012

MicroburstDSCF1501 (2)

Photographer: Claude Oesterreicher 
Summary Authors: Claude Oesterreicher; Jim Foster

The photo above showing a nasty looking storm was taken in DeKalb County, Illinois in the spring of 2010. I was on my way home from work when this huge rain shaft came into view. I observed several trees down farther west (left) of this location. When I got home (a few miles away), I noticed shingles missing from my roof and a wooden screen door had been ripped off my garage. This may have been a wet microburst. Microbursts impact areas no more than 2.5 mi (4 km) in width, with durations approximately a few minutes and can generate winds in excess of 100 mph (160 km/h). They result from intense downdrafts exiting the base of mature or, more often, dissipating thunderstorms. Downdrafts form when air within the storm, significantly cooled by rainfall, rushes to the surface. Because the spring of 2010 was very wet in northern Illinois, there were a lot of late plantings -- the field in the foreground had not yet been plowed. Photo taken at 3:40 p.m. on May 25, 2010.