Cumulonimbus clouds produce the thunderstorms we experience on the ground. Larry Jahn of Macomb, IL photographed this cumulonimbus along a frontal system on a flight from Seattle to O'Hare around 4:30 pm Wednesday, August 2 while passing over Iowa. Ironically, it wasn't Larry's last encounter with this weather system. After a quiet arrival in Chicago shortly taking this picture, the same disturbance unleashed thunderstorms on Chicago "with a vengeance", Larry reports, canceling a connecting flight to Moline. Cumulonimbus clouds are the tallest on the planet and can reach altitudes of 70,000 ft. at times. The cloud pictured here appears to be about 30,000 ft. tall. Thanks for the photos, Larry!
-Tom Skilling
PHOTO COURTESY: Larry Jahn, Macomb, Illinois
