Typically, turbulence within the cumulonimbus cloud will cause mammatus to form, especially on the underside of the ...

Formed by cold air sinking down, mammatus clouds are usually seen when there is turbulence in a cumulonimbus cloud. Two astronauts are returning home after nine months in space. Nick Beake of the ...

The name mammatus comes from the Latin mamma which means 'udder' or 'breast'. The bulging cloud was made to look even more dramatic with a fiery, orange glow from the sunrise. These clouds are ...

Formed by cold air sinking down, mammatus clouds are usually seen when there is turbulence in a cumulonimbus cloud. A US Coast Guard rescue swimmer was lowered to pull the woman as high waters ...

As this air rises, water vapor condenses to create a horizontal, rotating cloud that can resemble ocean waves or tsunamis.