Editing Nimbostratus cloud (section)

==Formation==
Nimbostratus occurs along a [[warm front]] or [[occluded front]] where the slowly rising warm air mass creates nimbostratus along with shallower stratus clouds producing less rain, these clouds being preceded by higher-level clouds such as [[cirrostratus]] and [[altostratus]].<ref name="dunlop">{{cite book|last=Dunlop|first=Storm|title=Weather Identification Handbook: The Ultimate Guide for Weather Watchers|publisher=Globe Pequot|location=Guilford, Connecticut|year=2003|isbn=1-58574-857-9}}</ref><ref name="earthscience">{{cite book|last=Thompson|first=Graham|author2=Turk, Jonathan |title=Earth Science and the Environment |publisher=Saunders College Publishing|location=Fort Worth|year=1993|isbn=0-03-075446-1}}</ref> Often, when an altostratus cloud thickens and descends into lower altitudes, it will become nimbostratus.<ref name="lankford">{{cite book|last=Lankford|first=Terry|title=Aviation Weather Handbook|publisher=McGraw-Hill Professional|year=2000|isbn=978-0-07-136103-3|url=https://books.google.com/books?id=kSSn7vPgmUQC&dq=nimbostratus+6500&cad=0}}</ref>

Nimbostratus, unlike cumulonimbus, is not associated with [[thunderstorm]]s, however at an unusually unstable warm front caused as a result of the advancing warm air being hot, humid and unstable, [[cumulonimbus]] clouds may be embedded within the usual nimbostratus. Lightning from an embedded cumulonimbus cloud may interact with the nimbostratus but only in the immediate area around it. In this situation with lightning and rain occurring it would be hard to tell which type of cloud was producing the rain from the ground, however cumulonimbus tend to produce larger droplets and more intense downpours. The occurrence of cumulonimbus and nimbostratus together is uncommon, and usually only nimbostratus is found at a warm front and sometimes in cold front.