Mammatus (also called mamma or mammatocumulus, meaning “mammary cloud”) is a cellular pattern of pouches hanging underneath the base of a cloud, typically a cumulonimbus raincloud, although they may be attached to other classes of parent clouds. The name mammatus is derived from the Latin mamma (meaning “udder” or “breast”).
Udderly incredible meteorological formation filmed over Córdoba, Argentina:
“Late Saturday afternoon the sky was covered with these unusual clouds that made us feel as if we were trapped in a vivarium, then came the strong storm with lightning, winds, and hail. We were lucky to have been there to capture this strange phenomenon, which may be a product of weather manipulation.”
images from wikipedia.org