Midwest U.S. Storm Clouds

July 12, 2012

 Storm clouds (1)
BenoitStorm480723_4303643755234_659987454_n (2)
Photographer: Bobbi Blake; Jamie Viebach
Summary Author: Jamie Viebach; Bobbi Blake; Jim Foster

The photos above were snapped as powerful thunderstorms roared through the upper Midwest of the U.S. on June 29, 2012. At top is a shelf cloud is approaching Oak Lawn, Illinois. The day before these storms hit, temperatures cracked the 100 F (38 C) mark all across Wisconsin and Illinois, as well as across much of the eastern two thirds of the U.S. Record heat, high dew points and a cold front positioned just west of Lake Michigan primed this area for volatile weather. Later on the 29th, a derecho sped eastward from just south of Lake Michigan all the way to the Atlantic Ocean. Winds from this fierce, fast moving storm system topped 65 mph (105 km/h) in Indiana, Ohio, West Virginia, Maryland, Virginia, and Delaware. Huge trees were toppled, some 250 years old, and power in some areas was out for a week, making for extremely uncomfortable living conditions.

The eerie looking clouds pictured at bottom, overhead Beloit, Wisconsin, may not actually be associated with the storm front. They appear to be undulatus asperatus, which traditionally don't result in stormy weather.