- Altocumulus cloud
Infobox Cloud
name = Altocumulus cloud
image location = Altocumulus02.jpg
abbreviation = Ac
symbol = CM_6.png
genus= Alto- ("high"), -cumulus ("heap")
species=
variety=
altitude_m = 2400-6100
altitude_ft = 8,000-20,000
level = medium-ish
appearance = Similar tocirrocumulus , but individual segments are larger and darker.
precipitation = No, but usually signifies an oncomingthunderstorm .Altocumulus ("Alto", "high", "cumulus", "heaped") is a
cloud belonging to a class characterized by globular masses or rolls in layers or patches, the individual elements being larger and darker than those ofcirrocumulus and smaller than those ofstratocumulus . Like othercumulus clouds , altocumulus signifies convection. It is usually white or gray, and often occurs in sheets or patches with wavy, rounded masses or rolls. Altocumulus often are seen preceding a cold front, and their presence on a warm, humid, summer morning frequently signals the development ofthunderstorms later in the day. Alto means high and these clouds may cause rain if they are higher up.One form of altocumulus, "altocumulus lenticularis" (
Lenticular cloud ) is frequently reported as "Unidentified flying object s".The altocumulus approach can sometimes be frightening, for the cloud has a dark and scary appearance. It about 8,000 feet to 20,000 feet above ground level.External links
* [http://www.clouds-online.com Clouds-Online.com Cloud Atlas with many photos and description of the different cloud genus]
* [http://www.nsdl.arm.gov/Library/glossary.shtml#Altocumulus National Science Digital Library - Altocumulus]
* [http://www.geographyinaction.co.uk/Assets/Photo_albums/Nine/pages/Altocumulus.html Altocumulus]
* [http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/mdl/altcu.rxml WW2010: University of Illinois] s
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