The ancients said, "It's cloudy in the sky and rainy on the ground. Rain comes from the ground and clouds come from the weather. " What does "cloudy weather" mean? What principle?

The appearance of clouds is composed of rain, and rain is composed of clouds in the sky, so the two are mutually rooted. Clouds in the sky become rain, which will inevitably reduce the number of clouds in the sky;

The rain on the ground rises to clouds, reducing the rain, so the two complement each other. Rain rises into clouds, and clouds fall into rain, which is the mutual transformation of yin and yang and the embodiment of the law of the rise and fall of yin and yang.

The generation and dissipation of extended data clouds and the evolution and transformation among various clouds are all carried out under certain water vapor conditions and atmospheric movement conditions. People can't see water vapor or atmospheric movement, but we can see every move of water vapor and atmospheric movement from the evolution of clouds, and water vapor and atmospheric movement play an extremely important role in weather phenomena such as rain, snow, freezing hail.

For thousands of years, the working people in our country have summed up the rich experience of "knowing the sky by observing the clouds" according to the changes in the shape, direction, moving speed, thickness and color of clouds in production practice, and compiled these experiences into proverbs.

Baidu Encyclopedia-Cloud