Cumulus cloud is described as?

• A. Wispy, feathery clouds
• B. Layered clouds that cover much of the sky
• C. Rain cloud; usually low, and formless
• D. Big, fluffy, white clouds that indicate fair weather; the more humid the air, the lower a cloud will form

Answer: (D)

Cumulus clouds appear as big, fluffy, white puffs with distinct edges and a flat base, formed when warm air rises. They usually signal fair weather when seen as separated clouds in a blue sky. As humidity increases, the air can sustain cloud formation lower in the atmosphere, so the cloud base lowers and the puff grows larger; if convection becomes strong, these clouds can develop into taller storm clouds. This description matches cumulus best: big, fluffy white clouds associated with fair weather and a lowering cloud base with more humidity. Other descriptions refer to different cloud types—wispy high-altitude clouds, layered overcast skies, or low, formless rain clouds.