| Cirrus fibratus  | |
|---|---|
| Abbreviation | Ci fib | 
| Symbol |   | 
| Genus | Cirrus (curl) | 
| Species | fibratus (fibered) | 
| Altitude | Above 6,000 m (Above 20,000 ft)  | 
| Classification | Family A (High-level) | 
| Appearance | fibers, threads [1] | 
| Precipitation | No | 
Cirrus fibratus, also called cirrus filosus, [2] is a type of cirrus cloud. The name cirrus fibratus is derived from Latin, meaning "fibrous". [3] These clouds are similar to cirrus uncinus, commonly known as "mares' tails," yet different in that fibratus clouds do not have tufts or hooks at the end. [4] The filaments are usually separate from one another. [5]
Like other cirrus clouds, cirrus fibratus occurs at high altitudes. They can indicate an approaching warm front [6] and can also be an indication that fair weather will follow. [7] Fibratus clouds indicate high, continuous winds up at cloud level.