Hierarchy classification:

1. top of the aat hierarchies
2. Associated Concepts Facet
3. Associated Concepts (hierarchy name)
4. scientific concepts
5. physical sciences concepts
6. earth sciences concepts
7. earth features
8. clouds

Anotations

Scope note:

The continuous rain cloud. Resulting from thickening Altostratus, This is a dark gray cloud layer diffused by falling rain or snow. It is thick enough throughout to blot out the sun. The cloud base lowers into the low level of clouds as precipitation continues. Also, low, ragged clouds frequently occur beneath this cloud which sometimes merges with its base.