Look at the clouds and know what the weather means.

It means that the change of the weather can be seen from the change of the clouds. It is said that the appearance of clouds is closely related to the change of weather. By observing different forms of clouds in the sky, we can know what kind of weather will be there.

Interpretation of "signboard" in Zhu Yongxi's "Looking at the weather through clouds": ontology: cloud; Metaphor: signboard. Similarity: both have indicating function. But the signboard is more obvious, closer to life and easy to understand. Therefore, signboards are used as metaphors and vivid images. The word "signboard" is used figuratively here.

Extended data "Clouds with different shapes and cloud base heights represent different weather. For example, stratocumulus (large area) indicates the weather phenomenon brought by a relatively stable large system. When this cloud appears.

Rainfall generally presents continuous characteristics; The appearance of cumulus clouds (smaller and deeper) represents the precipitation caused by small and medium-scale weather systems, including short-term heavy rainfall and even strong convective weather such as lightning or hail. If the height of cumulonimbus is greater than its width, it belongs to cumulonimbus, and the development of cumulonimbus is more vigorous. If it grows further, it may become a cumulonimbus cloud, and ice crystals will generally appear under it, indicating that precipitation will occur soon.