High and Low Clouds

A smattering of low cumulus clouds shown in this image in the foreground drift quickly past high altitude cirrus incinus (mare's tail clouds) in the background around 2:35 PM, Thursday, May 12, 2011. This view looks west from Brentwood Drive NE in Cedar Rapids, Iowa. Cirrus incinus clouds, which are composed of ice crystals and typically occur above 23,000 feet, usually presage the arrival of rain or stormy weather which did happen a day later.