In essence the cloud guide classification is that proposed by Luke Howard in 1803. This is based upon the altitude and visual appearance of each cloud. Firstly Howard used the following four Latin words as the basis:
- Cirrus – fibrous or hair like.
- Cumulus – a heap or pile.
- Stratus – a horizontal sheet.
- Nimbus – rain-bearing.
Secondly Howard combined these terms as necessary, and used the prefix alto for medium altitude clouds. Hence more cloud types were identified such as nimbostratus, altocumulus and cirrostratus.
The FSC Cloud name trail was produced in partnership with the Royal Meteorological Society.