The term "mackerel sky" refers to a specific type of cloud pattern characterized by a series of small, rounded, and wave-like clouds, often resembling the scales of a fish. This visual phenomenon is typically associated with altocumulus clouds, which are puffy, white clouds that can appear in rows, creating a textured sky.
While the answer suggests that "cumulonimbus" clouds are responsible for this appearance, it's important to note that cumulonimbus clouds primarily produce thunderstorms and have a very different structure compared to the layered, softer look of altocumulus clouds that form mackerel skies. Cumulonimbus clouds are tall, towering, and associated with severe weather events, which contrasts with the more benign and aesthetically pleasing nature of a mackerel sky.
Understanding the characteristics of cloud types helps in identifying the conditions under which different cloud formations occur, which is crucial in meteorology.