Cs compared with As
(Section 2.3.3.6.4)Cirrostratus is distinguished from Altostratus by:
- Being thin enough to show the disc of the Sun or Moon, except when the Sun or Moon is low on the horizon; Altostratus translucidus will reveal the position of the Sun or moon; Altostratus opacus will obscure the Sun or moon
- Being partly shaded or having no shading; Altostratus translucidus is partly shaded (Altostratus opacus is shaded throughout)
- Usual presence of halo phenomena
- No mamma
- No precipitation
- No virga