A mackerel sky refers to a weather phenomenon characterized by the appearance of a pattern of cirrocumulus or altocumulus clouds that resemble the scales of a mackerel fish. This term is derived from the old saying, ‘Mackerel sky, mackerel scales, make tall ships carry low sails.’
The cloud formation occurs when the upper atmosphere is filled with moisture and instability, indicating that a change in weather might be on the horizon. Typically, a mackerel sky can signal an incoming front, which could bring rain or a shift in wind patterns. These clouds often appear in a series of ripples or wave-like shapes, creating a striking and beautiful sky that can be mesmerizing to look at.
In summary, the term ‘mackerel sky’ is not only poetic but also serves as a useful observation tool for predicting weather changes, showcasing the dynamic nature of our atmosphere.