STRATUS/STRATO Layered, normally flat and smooth CUMULUS/CUMUL Puffy, cotton-wool CIRRUS/CIRRO Thin, wispy and hairlike ALTO Medium level NIMBUS/NIMBO Rain-bearing
+ 6000M (18,000FT)
Cirrus: White, silky hair-like clouds. Often form before a warm front or from aeroplane contrails, and some of the best for catching sunset colours.
Cirrocumulus: Group of regularly spaced out white cloudlets, sometimes called a mackerel sky. Usually appear in good weather but can hint at approaching storms.
Cirrostratus: Very wispy, hazy clouds.
2000-6000M (6500-18,000FT)
Altocumulus: Clumps or lines of cloudlets, look corrugated or like scales. White or grey, indicate settled weather.
Altostratus: Thin, spread-out, often grey, usually a sign that the weather will change.
Nimbostratus: Featureless and dense, bringing continuous rain.
0-2000M (6500FT)
Stratocumulus: Large masses of round clouds. Often indicate a weather front.
Cumulus: Fluffy white…