<P> Nimbostratus is a stratiform genus formerly classified as `` Family C '' low - level , but now considered by the World Meteorological Organization ( WMO ) to be a middle - or multi-level stratus type. . 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 . This change in classification would once have made it a `` Family D '' cloud , but this style of nomenclature was discontinued by the WMO in 1956 . Nimbostratus usually produces precipitation over a wide area . Nimbo - is from the Latin word nimbus , which denotes precipitation . It has a diffuse cloud base generally found anywhere from near surface in the low levels to about 3,000 m ( 9,800 ft ) in the middle level of the troposphere . Although usually dark at its base , it often appears illuminated from within to a surface observer . Nimbostratus usually has a thickness of about 2000 m . Though found worldwide , nimbostratus occurs more commonly in the middle latitudes . It is coded C 2 on the SYNOP report . </P>
<P> Nimbostratus is a stratiform genus formerly classified as `` Family C '' low - level , but now considered by the World Meteorological Organization ( WMO ) to be a middle - or multi-level stratus type. . 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 . This change in classification would once have made it a `` Family D '' cloud , but this style of nomenclature was discontinued by the WMO in 1956 . Nimbostratus usually produces precipitation over a wide area . Nimbo - is from the Latin word nimbus , which denotes precipitation . It has a diffuse cloud base generally found anywhere from near surface in the low levels to about 3,000 m ( 9,800 ft ) in the middle level of the troposphere . Although usually dark at its base , it often appears illuminated from within to a surface observer . Nimbostratus usually has a thickness of about 2000 m . Though found worldwide , nimbostratus occurs more commonly in the middle latitudes . It is coded C 2 on the SYNOP report . </P>
what is meant by the term nimbus regarding clouds
what is meant by the term nimbus regarding clouds
precipitation
precipitation