What are the three stages of light snow?

In ancient times, light snow was divided into three stages: one stage when the rainbow disappeared; Second, the weather is rising; Third-class clearance, full winter. It means: due to the drop in temperature, it is snowy below the north, no more rain, and no rain rainbow can be seen; Because of the rising of the yang in the sky and the falling of the yin in the ground, yin and yang do not meet, and heaven and earth are blocked; So heaven and earth became one, and it became a cold winter.

"Light Snow" is a festival that reflects weather phenomena. "Xiaoxue" is in the second half of the solar calendar 1 1 and the second half of the lunar calendar in October. There is little snow, and there is no snow on the ground. This is the original meaning of the solar term "light snow". The ancient book "Qunfangpu" says: "Light snow will snow when it is cold, and it will not even snow on the ground, and the snow is not big." In other words, due to the cold weather, the form of precipitation changed from rain to snow in the "light snow" festival, but at this time, because the ground is not very cold, the number of snows is small and the amount of snow is not large, so it is called light snow. So light snow indicates the beginning time and degree of snowfall. Light snow, like rain and Grain Rain, is a solar term that directly reflects precipitation.