A cumulonimbus incus cloud has a characteristic anvil-top shape.

A cumulonimbus incus is a cumulonimbus cloud which has reached the level of stratospheric stability and has formed the characteristic anvil-top shape. If the atmospheric updraft is strong enough, it can bypass the stratospheric stability and become a pileus. Image File history File links Download high resolution version (1280x960, 1300 KB)Ideal Anvil Cloud. ... Image File history File links Download high resolution version (1280x960, 1300 KB)Ideal Anvil Cloud. ... Cumulonimbus cloud in central Oklahoma. ... The tropopause is a boundary region in the atmosphere between the troposphere and the stratosphere. ... A pileus (Latin for cap) is a small, horizontal cloud that can appear above a cumulus or cumulonimbus cloud, giving the parent cloud a characteristic hoodlike appearance. ...