An amorphous, dark grey, rainy cloud layer reaching almost to the ground; \(300{-}600\ \text{m}\) vertical velocities of \(0.05{-}0.2\ \text{m s}^{-1}\).
Source: PAC, 1990,
62, 2167. (
Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2180 [
Terms] [
Paper]