Cumulus typically has distinct rounded tops and a darker, nearly level base. Sunlit parts can look bright white, and a growing cloud may develop taller domes. The photographed small, shallow clouds are examples of cumulus humilis, within the cumulus genus.
This is our first choice for beginning a cloud notebook: pick one cloud, sketch its base and outline, and compare it with a later view. The contrast between separate heaps and layered clouds is easy to practise. Do not assume every cumulus stays small or guarantees a dry afternoon.
Photo: Toby Hudson · CC BY-SA 3.0. Resized and recompressed; image retains its source license.
