Downward-growing nimbostratus can have the same vertical extent as most large upward-growing cumulus, but its horizontal extent tends to be even greater.
32.
Usually, nimbostratus is a sign of easily steady to powerful precipitation, as opposed to the shorter period of typically heavier precipitation released by a cumulonimbus cloud.
33.
Nimbostratus usually produces precipitation over a wide area . " Nimbo-" is from the Latin word " nimbus ", which denotes precipitation.
34.
Frontal cirrostratus is a precursor to rain or snow if it thickens into mid-level altostratus and eventually nimbostratus as the weather front moves closer to the observer.
35.
The exceptions include altostratus that has varieties but no species, towering cumulus and cumulonimbus that have species but no varieties, and nimbostratus has no species or varieties.
36.
It retains the same features as a normal nimbostratus cloud; dark in appearance, low to medium level cloud of moderate vertical development and made up of sheets.
37.
Multi-�tage types or sub-types not limited by altitude include cumulonimbus-Cb, towering cumulus-Tcu ( not shown ), and nimbostratus-Ns.
38.
Of the latter, " upward-growing " cumulus mediocris produces only isolated light showers, while " downward growing " nimbostratus is capable of heavier, more extensive precipitation.
39.
It was then renamed " nimbostratus, " and published with the new name in the 1932 edition of the " International Atlas of Clouds and of States of the Sky ".
40.
Curtis Roads suggests a taxonomy of cloud morphology based on atmospheric clouds : cumulus, stratocumulus, stratus, nimbostratus, and cirrus; as well as nebulae : dark or glowing, amorphus or ring-shaped, and constantly evolving.
