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Height of base:

Between 600 and 2000 m (2000-6500 ft) (low-level clouds)


Distinct layer of heaps and rolls,

dark shading in base; bright on top

loose layers, elements are touching

>5 across, larger than the width of 3 fingers across at 30 above horizon


World-wide; most common cloud genus

Made of:

water droplets


Mostly none; occasionally light rain or snow reaching ground


-          cumulus can join by accumulating under a temperature inversion

-          stratus can develop thermals by preferential temperature increase at bottom versus colder tops


Stratiformis, lenticularis, castellanus


Opacus, translucidus, perlucidus, undulatus, duplicatus, radiatus, lacunosus

How to distinguish from

Cumulus (Cu)

Cu do not touch, Sc has flatter top

Altocumulus (Ac)

Cloud elements are smaller than 3 fingers width at 30 above horizon

Higher than 2000 m

Stratus (St)

St indistinct layer with much less variation in tone than Sc layer


Stratocumulus with embedded congestus and

Calvus (see rain core)

Morris, Sep06

Stratocumulus stratiformis perlucidus

(Morris, November 2006)

Stratocumulus stratiformis opacus

(Morris, January 2007)


End of passage of a warm front

Glenwood, Sep 08


Stratocumulus castellanus

Morris, July07







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Last modified: 1/18/2008

Maintained by Sylke Boyd


The views and opinions expressed in this page are strictly those of the page author. The contents of this page have not been reviewed or approved by the University of Minnesota.