List of cloud types
Clouds of the genus stratus form in low horizontal layers having a ragged or uniform base. Ragged stratus often forms in precipitation while more uniform stratus forms in maritime or other moist stable air mass conditions. The latter often produces drizzle. Stratus that touches the Earth's surface is given the common name, fog, rather than a Latin name that applies only to clouds that form and remain aloft in the troposphere."Cloud types are sorted in alphabetical order except where noted".
The division of genus types into species is as shown in the following table. The species are sorted from left to right in approximate ascending order of instability or vertical extent. The genus types are arranged from top to bottom in the same ascending order of instability within each étage. (1)=Stratiform types, (2)=Cirriform types, (3)=Stratocumuliform types, (4)=Cumuliform types, (5)=Cumulonimbiform types.
Vert=Vertical or multi-level, MV=Moderate or deep vertical, TV=Towering vertical.
Castellanus
Castellanus that are unfavourable to soaring can be easily identified and are nicknamed ""rocket clouds"."
The visual difference between a cumulus and a castellanus is that the former has a flat base while the latter generally has no clearly defined base. However, a visual observation of the cloud may not be sufficient, since in some cases the hybrid castellanus (pseudo cumulus) may have a flat base. The only sure way to distinguish between these two types of clouds is through an atmospheric sounding preceding the flight. If the base of these false cumulus is higher than the convective condensation level, the pilot is probably close to unwanted cumulonimbus. Moreover, when a cumulus breaks down, there may still exist an updraft column under the cloud base that did not originate from the ground. In particular, at the end of the day, the airmass can be stable up to 2000 feet and unstable above this stable layer. The cumulus turn into stratocumulus or altocumulus depending on their height. Before the 1956 version of the International Cloud Atlas, these clouds were called stratocumulus or altocumulus "vesperalis". Directly under these clouds, updrafts are still present. The meteorologist Corfidi explains that these seemingly innocuous clouds that break down rapidly can be a harbinger of nocturnal thunderstorms.