C_L = 1

(a) TECHNICAL SPECIFICATION

Cumulus humilis or Cumulus fractus of dry weather or both.

Humilis: little vertical extent and seemingly flattened.

Fractus: ragged.

(“Dry weather” denotes conditions without precipitation.)

(b) EXPLANATION

The clouds corresponding to the code figure C_L = 1 include the following:

(i) Cumulus in the initial stages of formation or in the last stages of dissipation.

(ii) Cumulus completely formed but frayed by a fairly strong and sufficiently turbulent wind; these Cumulus fractus are well separated and generally look white. The difference between these clouds and Cumulus fractus of wet weather is indicated in the explanation on specification C_L = 7.

(iii) Cumulus completely formed with clear-cut horizontal bases; these clouds have either a flattened or deflated form, or show somewhat rounded tops without a cauliflower appearance.