The presence of altocumulus undulatus may indicate precipitation within the next 20 hours or simply an overcast day.
12.
I believe they are altocumulus clouds, and if anyone can confirm that, then that would be wonderful.
13.
Extensive altocumulus formations, particularly if they take the form of undulatus are often referred to as altocumulus mackerel sky.
14.
Extensive altocumulus formations, particularly if they take the form of undulatus are often referred to as altocumulus mackerel sky.
15.
Layered forms of altocumulus are generally an indicator of limited convective instability, and are therefore mainly stratocumuliform in structure.
16.
For example, middle cumulus clouds are called " altocumulus " and high stratus clouds are " cirrostratus ."
17.
Altocumulus with circular holes caused by localized downdrafts; normally associated with stratiformis and castellanus species ( also with cumuliform floccus species ).
18.
C . S . T ., on the 22d with altocumulus and alto-stratus overcast showing through breaks occasionally during the day.
19.
Cirrocumulus is distinguished from altocumulus in several ways, although the two stratocumuliform genus types can occasionally occur together with no clear demarcation between them.
20.
If unstable altocumulus castellanus accompanies or takes the place of the main altostratus layer, cumulus congestus or cumulonimbus producing showers or thunderstorms may follow.
