I remember looking at the sky and being able to identify what kind of clouds they were. I forgot most of that now.

Clouds are classified into four families:

  • High Clouds
  • Middle Clouds
  • Low Clouds
  • Clouds of Vertical Development

Clouds are also identified by the way in which they form: cumulus and stratus.

Cumulus Clouds: Form in rising air currents and are evidence of unstable air conditions

  • Lumpy and Cotton-like

Stratus Clouds: Form in horizontal layers and are usually form as a layer of moist air is cooled below its saturation point

  • Slow-moving Air / stable air

Nimbus Clouds: Clouds from which prepicipation falls

High Clouds (Cirro-)

Range from 16,500 feet to 45,000 feet, averaging about 25,000 feet. Composed of ice crystals.

  • High clouds have little effect on flying, moderate turbulence might be experienced

Cirrus (Ci) Cirroculumus (Cc) Cirrostatus (Cs)

Middle Clouds (Alto-)

Range from 6,500 feet to 23,000 feet, averaging about 25,000 feet. Composed of ice crystals or water droplets.

Altocumulus (Ac) Altocumulus Castellanus (Acc) Altostratus (As)

Low Clouds (Strato-)

Range from surface height to 6,500 feet. Composed of waterdroplets that may be Supercooled and sometimes of ice crystals. Stratus (St) Stratocumulus (Sc) Nimbostratus (Ns)

Clouds of Vertical Development

Cumulus (Cu) Cumulus Fractus (Cf)