NIMBUS

A nimbus cloud is a multi-level, gray, often dark, amorphous, nearly uniform cloud that usually produces continuous rain, snow, or sleet and no lightning or thunder. Although it is usually a low-based cloud, it actually forms most commonly in the middle level of the troposphere and then spreads vertically into the low and high levels. Nimbus clouds usually produces precipitation over a wide area. Nimbo- is from the Latin word nimbus, which denotes precipitation.