Cirrostratus / ˌ s ɪr oʊ ˈ s t r ɑː t ə s / 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.
Cirrus castellanus is a species that has cumuliform tops caused by high-altitude convection rising up from the main cloud body. Cirrus fibratus looks striated and is the most common cirrus species. Cirrus uncinus clouds are hooked and are the form that is usually called mare's tails.
The cumulonimbus base may extend several miles across and occupy low to middle altitudes - formed at altitude from approximately 200 to 4,000 m (700 to 10,000 ft). Peaks typically reach to as much as 12,000 m (39,000 ft), with extreme instances as high as 21,000 m (69,000 ft) or more.
Cumulus congestus clouds have a cauliflower-like structure and tower high into the atmosphere, hence their alternate name "towering cumulus". The variety Cumulus radiatus forms in radial bands called cloud streets and can comprise any of the four species of cumulus.
Nimbostratus has a diffuse cloud base generally found anywhere from near surface in the low levels to about 3,000 m (9,800 ft) in the middle level of the troposphere. Although usually dark at its base, it often appears illuminated from within to a surface observer. Nimbostratus usually has a thickness of about 2000 to 4000 m.
Stratocumulus Perlucidus is a layer of stratocumulus clouds with small spaces, appearing in irregular pattern, through which clear sky or higher clouds can be seen. Stratocumulus Translucidus consist of separate groups of stratocumulus clouds, with a clear sky (or higher clouds) visible between them.
Stratus clouds are low-level clouds characterized by horizontal layering with a uniform base, as opposed to convective or cumuliform clouds that are formed by rising thermals. More specifically, the term stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color from dark gray to nearly white.