Very dark cloud
A billow cloud typically signals strong winds and turbulence in the atmosphere. This type of cloud formation often occurs ahead of a cold front and can indicate the potential for thunderstorms and severe weather.
It's a type of thunderstorms
Cumulonimbus Cloud
the symbol for thunderstorms is a capital T with a circle around it.
A cumulonimbus cloud
thunderstorms.
the storm cloud
As with all thunderstorms, a supercell takes the form off a cumulonimbus cloud.
Thunderstorms form in the troposphere. The tops of strong thunderstorms may go into the stratosphere.
Thunderstorms and tornadoes, whether they are quick or not, are the product if cumulonimbus clouds.
A cumulonimbus cloud
easy !! Cumulus Clouds