Spissatus

Spissatus is a Latin term meaning thick or dense. In meteorology, it is used as a descriptive species name within the World Meteorological Organization cloud classification to indicate unusually dense or veil-like variants of a cloud genus. It is not a genus itself, but a label appended to a genus to describe the cloud’s apparent density and coverage.

Common combinations include Cirrus spissatus, Altocumulus spissatus, and Stratus spissatus. These denote high-, mid-, or low-level clouds that appear unusually dense for their genus, often producing an extensive, uniform appearance that may obscure the sun or sky.

Cirrus spissatus forms as a thick veil of ice crystals at high altitude, typically producing little or no precipitation but indicating moisture aloft. Stratus spissatus is a low, dense layer resembling fog that does not touch the ground, potentially bringing light drizzle. Altocumulus spissatus appears as a dense sheet or patches in the mid troposphere and commonly accompanies overcast conditions.

Etymology: from Latin spissus meaning thick. In modern meteorology, spissatus remains a descriptive term within cloud taxonomy rather than a standalone cloud type. Its recognition helps forecasters describe sky conditions and potential weather development.