This document describes different types of clouds and cloud formations. It provides definitions and characteristics for various low, middle, and high clouds including wave clouds, shelf clouds, wall clouds, tornadoes, mammatus clouds, cumulonimbus clouds, cumulus clouds, stratocumulus clouds, stratus clouds, altocumulus clouds, altostratus clouds, nimbostratus clouds, cirrus clouds, cirrostratus clouds, and cirrocumulus clouds. It also includes a skywatcher chart showing typical cloud types at different elevations from the ground.

1. WaveCloud
Formedbystronghorizontal
windsoveruneventerrain
ShelfCloud
Representstheleadingedge
ofstrongwindsinadvance
ofathunderstorm
WallCloud
Loweringoftherainfree
baseofathunderstorm,often
priortotornadoformation
Tornado
Rapidlyrotatingcolumn
underacumulonimbuscloud
thattouchestheground
Mammatus
Droopingundersideof
heavy,rain-saturatedclouds
L9:Cumulonimbus
Withfibroustop,often
withananvil
L8:Cumulus&Stratocumulus
Notspreading,basesat
differentlevels
L7:StratusFractus
and/orCumulusFractus
occurswithrainorsnow
L6:Stratus
Inacontinuouslayer
and/orraggedshreds
L5:Stratocumulus
Notfrom thespreading
andflatteningofcumulus
L4:Stratocumulus
From thespreadingand
flatteningofcumulus
L3:Cumulonimbus
Topsnotfibrous,outlinenot
completelysharp,noanvil
L2:Cumulus
Moderate/strongvertical
extent,ortoweringcumulus
L1:Cumulus
Cumulusoffairweather
withflattenedappearance
M9:Altocumulus
Chaoticsky,cloudbases
atseverallevels
M8:Altocumulus
Withcumulus-liketufts
orturrets
M7:Altocumulus
Oneormoreopaquelayers,
w/altostratusornimbostratus
M6:Altocumulus
From thespreadingof
cumulusorcumulonimbus
M5:Altocumulus
Oneormorebandsorlayers,
expanding,thickening
M4:Altocumulus
Lens-shaped,orcontinually
changingshapeandsize
M3:Altocumulus
Semi-transparent,onelevel,
cloudelementschangeslowly
M2:Altostratusor
Nimbostratus
Denseenoughtohide
thesunormoon
M1:Altostratus
Mostlysemi-transparent,sun
ormoonmaybedimlyvisible
H9:Cirrocumulus
Aloneorwithsomecirrus
orcirrostratus
H8:Cirrostratus
Notincreasing,not
coveringthewholesky
H7:Cirrostratus
Translucent,completely
coveringthesky
H6:Cirrostratus
Cirrusbands,increasing,
veilabove45°elevation
H5:Cirrostratus
Cirrusbands,increasing,
below45°elevation
H4:Cirrus
Inhooksorfilaments,
increasing,becomingdenser
H3:Cirrus
Oftenanvilshapedremains
ofacumulonimbus
H2:Cirrus
Dense,inpatchesorsheaves,
notincreasing,orwithtufts
H1:Cirrus
Intheform offilaments,
strands,orhooks
LowClouds:cloudbasesUpto6,500ft(0-2km)
MiddleClouds:cloudbases6,500-23,000ft(2-7km)
HighClouds:cloudbases16,000-50,000ft(5-15km)
SpecialphotocreditthankstoJimW.Lee,EricKurth,BrianKlimowski,andEricHelgeson
http://www.weather.gov/os/brochures/cloudchart.pdf
TypicalTypes:Stratus(St),Stratocumulus(Sc),Cumulus(Cu),Cumulonimbus(Cb)
TypicalTypes:Altostratus(As),Altocumulus(Ac),Nimbostratus(Ns)
TypicalTypes:Cirrus(Ci),Cirrostratus(Cs),Cirrocumulus(Cc)
SKYWATCHERCHART