The Web Yellow Pages HOME Tornado terminology Accessory Clouds Clouds that are dependent on a larger cloud system for development and continuance.
Accessory clouds associated with the thunderstorm include roll, shelf, mammatus, and wall clouds.
The spreading of the upper portion of a cumulonimbus cloud into an anvil-shaped plume usually of fibrous or smooth appearance. Strong or severe thunderstorms often have thicker anvils with the side and bottom having a cumuliform or slowly boiling appearance in the immediate vicinity of the parent cumulonimbus. Bear's cage Storm chasers use this term to describe the region of storm-scale rotation in a thunderstorm which is wrapped in heavy precipitation. The term reflects the danger involved in observing such an area visually, which must be done at close range in low visibility. Collar Cloud Frequently used as a synonym for wall cloud, although it actually is a generally circular ring of cloud surrounding the upper portion of a wall cloud.