What is a cloud without rain and wind in a fish-scale sky?
It means that the clouds in the sky are like scales, indicating rain or wind. It is a proverb that "it is windy even if it doesn't rain". Fish-scale sky means that the clouds in the sky are arranged one by one like fish scales. Meteorologically, this kind of cloud is called cumulus cloud, which mostly occurs on the front of low pressure. Generally speaking, there will be a low pressure heading north in the next 24 hours, the sky will be unstable and the weather will turn bad. Even if it doesn't rain, it will be windy.
Generally speaking, in translucent cumulus clouds, before the arrival of cold air, the clouds gradually thicken and distribute in layers. When thick clouds "squeeze" each other, they will appear fish-scale clouds. Meteorologists say that this scale cloud will become a rain cloud when it accumulates to a certain extent. The meteorological proverb vividly says, "it's a fish-scale day, and it's windy without rain." After the "fish scale cloud" is formed, there are often showers.
The appearance of fish scale clouds means that the weather will change, and it may rain, wind and snow. So the meaning of this sentence is that even if it doesn't rain and fish scale clouds appear in the sky, we should be alert to weather changes and guard against the influence of bad weather such as strong winds.
Formation principle of translucent cumulus clouds
The formation of fish scale weather, no rain and wind turbulence is related to specific meteorological conditions, mainly including atmospheric stability and high humidity. One possible formation principle is that wet air takes off under stable atmospheric conditions, and when the air rises, it will experience changes in temperature and pressure. At a certain height, the air is saturated, and water vapor condenses into water droplets, forming clouds.
Take fish scales as an example. These clouds are usually stratocumulus clouds or cirrus clouds, which show the characteristics of large area, uniform size and neat arrangement, and are shaped like fish scales. This may be due to the specific atmospheric circulation leading to the arrangement and shape of clouds. At the same time, the characteristics of "no rain and no wind" suggest that in this weather situation, although the clouds are densely covered, there is no precipitation, but strong winds blow the clouds. This may be because of the influence of the local wind field, and the strong wind makes the clouds blown, stirred or vibrated.