Old people often say that "the southern clouds get up early and the northern clouds accumulate late". Is it really reasonable?

This is a proverb in ancient agricultural knowledge, which should be applicable and reasonable in the social and historical background at that time, but in modern times, with more authoritative weather forecasting institutions, it will be suspected.

Meteorological knowledge in speech: Don't go out at sunrise, but go to Wan Li Road at sunset. Lei Gongyan cried, and the rain was coming. ? If it doesn't rain in Grain Rain, return it to the owner. The loach jumps and the wind and rain come. The sun rises in the eastern rainbow and the rain falls in the western rainbow. The sun is dizzy in the middle of the night, the rain is dizzy, and the moon is dizzy at noon. The carp in the sky points, and the sun and the valley turn differently. Long sunny and foggy, long cloudy and foggy. ? I'm afraid that Nanyun will get up in the morning and Beiyun will pile up at night. In the morning, the sea clouds rise and the wind and rain suddenly rise. The clouds fell early, and it was sunny the next day after dinner. The south wind is afraid of flooding and the north wind is afraid of heat. Strong winds last for a long time in sunny days and for a long time in rainy days.

Besides words, there are many ancient poems. For example, even if there is no rain in Enigma, clothes are stuck in the depths of the clouds; Jiangnan in February is full of flowers, and the cold food in other places is far from sad; I don't hate carving jade feathers, and the south of the Yangtze River is warm and the west of Gansu is cold; There is no turning back when you go through the customs.

Water vapor condenses into small water droplets when it meets cold air at high altitude. These small water droplets are very small, with a diameter of only 0.0 1 ~ 0.02 mm and a maximum of only 0.2 mm ... They are small and light, and are held up in the air by the updraft in the air. It is these small water droplets that gather in the air to form clouds. These small water droplets will become raindrops and fall to the ground, and the volume will increase by about 1 10,000 times. Ancient people also had a lot of unexpected wisdom to predict the arrival of rainy days, but it is rarely used in modern times.