What scientific principles are contained in weather proverbs?

1, "East Rainbow Sun West Rainbow Rain"

Most of China is located in the north temperate zone, and the westerly airflow prevails at high altitude. Affected by the westerly airflow in the upper air, the cloud system of rainfall generally moves from west to east. Therefore, if you see a rainbow in the east at night, it means that the rain area has moved eastward. The local weather will clear up. If there is a rainbow in the west in the morning, it means that there are more water droplets in the air in the west and the rain area is about to move. The weather is about to get worse. Therefore, it is reasonable to say that "the sun in the east rainbow and the rain in the west rainbow" is a phenomenon brought by the rain cloud system moving from west to east.

2, "carp rain in the sky, don't turn it tomorrow."

The lower atmosphere is unstable, while the upper atmosphere is stable. In this case, it is particularly beneficial to the formation of Apollo Cloud. Because the upper and lower layers of air are stable, it is not conducive to the formation of fluctuations. If the air in the upper and lower layers is unstable, it is not fluctuation, but convection. The unstable air layer in the lower layer and the stable air layer in the upper layer not only ensure that the disturbed air has a certain vertical movement, but also will not develop into convection. It can be seen that the appearance of wave clouds often indicates that the upper atmosphere is very stable, so it will be sunny.