Stratocumulus (Sc)


Source: http://mmem.spschools.org/grade5science/weather/stratocumulus.html

Level: Below 6,500 ft.

Composition: Water

Typical Conditions: Atmosphere with moist lower-levels but an inversion preventing clouds from growing into the mid-levels and higher. Sometimes a prelude to significant precipitation or thunderstorms, but not always.

Appearance: Similar to stratus, but with distinct, individual "lumps" instead of a uniform layer. Although they can be confused with altocumulus, the lumps are significantly larger to a ground observer (because of the lower height). A common test is to extend one's arm out towards the sky and make a fist: if a lump in the clouds is similar in size to the entire hand (or larger), it is likely stratocumulus; if it's significantly smaller, about the size of a finger, it is likely altocumulus.