Cloud murus cloud and is the result of air feeding into the storm. Supplementary cloud formations detached from the main cloud are known as accessory clouds. The heavier precipitating clouds, nimbostratus, towering cumulus (cumulus congestus), and cumulonimbus typically see the formation in precipitation of the "pannus" feature, low ragged clouds of the genera and species cumulus fractus or stratus fractus. A group of accessory clouds comprise formations that are associated mainly with upward-growing cumuliform and cumulonimbiform clouds of free convection. "Pileus" is a cap cloud that can form over a cumulonimbus or large cumulus cloud, whereas a "velum" feature is a
Cirrostratus cloud Cirrostratus cloud Cirrostratus is a high-level, very thin, generally uniform "stratiform" genus-type of cloud, composed of ice-crystals. It is difficult to detect and is capable of forming halos when the cloud takes the form of thin cirrostratus nebulosus. The cloud has a fibrous texture with no halos if it is thicker cirrostratus fibratus. On the approach of a frontal system, the cirrostratus often begins as nebulosus and turns to fibratus. If the cirrostratus begins as fragmented fibratus it often means the front is weak. Cirrostratus is usually located above 5.5 km (18,000 ft). Its presence indicates a large amount of