A severe thunderstorm, cumulonimbus cloud, moves across the plains east of Denver on June 10, 2004. Heavy rain and large hail is falling in the background, dark blue or blue-green area. A downdraft of cool, moist air produced by the rain and hail is pushing toward the camera. The strong winds produce fragmented cumulus clouds known as fractocumulus or scud, lighter, lower clouds in foreground.
