Liquid water content useful for weather forecasting as cumulonimbus clouds are related to thunderstorms and heavy rain whereas cirrus clouds are not directly associated with precipitation. The liquid water content of a cloud varies significantly depending on the type of clouds present in the atmosphere at a given location. The classification of the cloud is highly related to the liquid water content as well as the origin of the cloud. The combination of these two allows a forecaster to more readily predict the types of conditions that will be in an area based on the types of clouds that are forming or have
Cloud of a squall line or thunderstorm outflow. A large arcus formation can have the appearance of a dark menacing arch. Several new supplementary features have been formally recognized by the World Meteorological Organization (WMO). The feature "fluctus" can form under conditions of strong atmospheric wind shear when a stratocumulus, altocumulus, or cirrus cloud breaks into regularly spaced crests. This variant is sometimes known informally as a Kelvin–Helmholtz (wave) cloud. This phenomenon has also been observed in cloud formations over other planets and even in the sun's atmosphere. Another highly disturbed but more chaotic wave-like cloud feature associated with stratocumulus or