FTP, name this type of cloud associated with severe thunderstorms.
These clouds sometimes display a form referred to as mamma, where bulbous protrusions hang from the base of the cloud. Larger ones sometimes have a feature technically referred to as cirrus spissatus, or more commonly referred to as an anvil. It is classified as a low cloud due to the height of its base, but occasionally its top can reach the tropopause. FTP, name this type of cloud associated with severe thunderstorms.
These clouds sometimes display a form referred to as mamma, where bulbous protrusions hang from the base of the cloud.
cumulonimbus (do not accept or prompt on "nimbus")