Definition

PRECIPITATION, often short-lived and heavy, falling from convective CLOUDS; the drops or solid particles in showers are usually bigger than the corre­sponding elements in other types of PRECIPI­TATI­ON. Showers are characterized by their sudden begin­ning and ending, generally by large and rapid changes of intensity, and, most frequently, by the appearance of the sky; namely, rapid alternations of dark, mena­cing CLOUDS (cumulonimbus) and of CLEARANCES of short dura­tion.