Taking My Lumps

This image of lumpy mammatus clouds over two other cloud types was taken from the grounds at Noelridge Christian Church in Cedar Rapids, Iowa around 3:55 PM, Sunday, May 22, 2011 and looks northeast. The presence of mammatus clouds indicate a very moist and unstable middle or upper level in the atmosphere which overlies a drier layer below a cumulonimbus anvil. In this condition, convection is inverted as instability is forced downward out of the parent cloud, not up. Large amounts of moisture and heat bubble out from a cumulonimbus anvil over the neighboring, relatively undisturbed air. Also seen in this image is a pileus cloud capping structure seen just above the low level scud clouds in front. Pileus clouds form in strong updrafts within moist air at lower altitudes.