Cirrus: high level, white tufts or filaments; made up of ice crystals. (No precipitation.)
Cirrocumulus: high level, small rippled elements; ice crystals. (No precipitation.)
Cirrostratus: high level, transparent sheet or veil, halo phenomena; ice crystals. (No precipitation.)
Altocumulus: middle level layered cloud, rippled elements, generally white with some shading. May produce light showers.
Altostratus: middle level grey sheet, thinner layer allows sun to appear as through ground glass. Precipitation: rain or snow.
Nimbostratus: thicker, darker and lower based sheet. Precipitation: heavier intensity rain or snow.
Stratocumulus: low level layered cloud, series of rounded rolls, generally white. Precipitation: drizzle.
Stratus: low level layer or mass, grey, uniform base; if ragged, referred to as "fractostratus". Precipitation: drizzle.
Cumulus: low level, individual cells, vertical rolls or towers, flat base. Precipitation: showers of rain or snow.
Cumulonimbus: low level, very large cauliflower-shaped towers to 16 km high, often "anvil tops". Phenomena: thunderstorms, lightning, squalls. Precipitation: showers of rain or snow.