Precipitation

Precipitation, in meteorology, is any type of water that falls from the sky as weather. This includes snow, rain, sleet, freezing rain and hail. Precipitation is a major part of the water cycle[?], and is responsible for depositing most of the fresh water on the planet. Precipitation is generated in clouds, which reach a point of saturation; at this point larger and larger droplets (or pieces of ice) form, which then fall to the earth under gravity. It is possible to 'seed' clouds to induce precipitation by releasing a fine dust or appropriate chemical (commonly silver nitrate) into a cloud, encouraging droplets to form, and increasing the probability of precipitation.

In chemistry, precipitation is the condensation of a solid from a solution. This occurs when the solution is saturated, whereupon the solid forms, and usually sinks to the bottom of the solution.

See also umbrella.