What is the scientific basis for the lunar calendar' 65438+February' in Songyang County, Lishui?

"The third day is sunny, the sixth day is snowy" is an agricultural proverb, which is not only found in Songyang County of Lishui, but also in many areas around Zhejiang. Some are called "It snows on the sixth day of the third grade". It means that if the sun opens its eyes on the third day of the twelfth lunar month, it will usually snow on the sixth day. I have known this agricultural proverb since I was a child, and sometimes it is really accurate. I really admire the wisdom of our ancestors.

Speaking of scientific basis, this is related to the geographical location and winter climate of Zhejiang, which is often one of the areas where cold and warm air are intertwined. Generally, before the arrival of strong cold air in winter, the temperature will be higher. The cold air from northern Siberia moves south, and a strong dry and cold airflow moves from north to south. When its leading edge comes into contact with the warm and humid air in the south, because the cold air is heavier than the warm air, it will lift the warm and humid air to high altitude, so that the water vapor in the warm air will quickly condense into ice crystals and then gradually increase into snowflakes.