Squall

Low clouds: Cumulonimbus 1

Illustration of cumulonimbus clouds, tall, dense, and involved in thunderstorms and other intense weather. Cumulonimbus means "column rain" in Latin. It is a result of atmospheric instability. These clouds can form alone, in clusters, or along a cold front in a squall line. They create lightning through the heart of the cloud. Cumulonimbus storm cells can produce heavy rain (particularly of a convective nature) and flash flooding, as well as straight-line winds