Why do Guangdong people call wet weather "going back to the south"?
Returning to Nantian is very common in Guangdong, almost every spring. In winter and spring, Chinese mainland, including Guangdong Province, is mostly controlled by Siberian dry and cold air mass. Of course, it is a spent force for the cold air from the north to go down to Guangdong, and the temperature is not too low, but this cold air can completely control the whole Lingnan area, and even the small islands in Southeast Asia will be affected. Generally speaking, dry and cold air from the Mongolian Plateau and Siberia will dominate in winter, pushing warm and humid air from the South China Sea to the South Pacific.
It usually occurs in February and March in Guangdong in spring, mainly because of the rapid action of warm and humid airflow after cold air, which leads to the rapid increase of temperature and air humidity. Some cold objects are prone to produce water droplets after encountering warm and humid airflow, which is also commonly known as vomiting. Thick fog is the most distinctive appearance of Huannantian.
The formation principle of Huinantian is the same as that of dewdrops, that is, dewdrops are bound at home and on walls, floors and furniture. There are at least two conditions for the formation of obvious empty space: first, there must be a long-term low temperature, and the daily average meteorological temperature is lower than 12℃ for at least 3 days.
For example, before returning to Nantian in February of 20 10, the daily average temperature was lower than 12℃ for 9 consecutive days. Secondly, the weather is bound to change suddenly. After a long period of low temperature, it will suddenly become warm and humid. Back to the south, the humidity sometimes reaches 100%.
The weather process in South China is also a process in which the warm and humid southerly airflow repels the northern system in a large area. Around the southern sky, the temperature rose rapidly, the air pressure dropped sharply, the wind speed increased sharply, the visibility plummeted, and the humidity tended to be saturated.
"Returning to Nantian" is formed in stable weather, and the phenomenon of "returning to Nantian" mainly occurs in the near-surface layer. There are two stages in the occurrence of "returning to Nantian": the early stage of low temperature and rainy weather and the stage of warming and humidifying before and after "returning to Nantian". Before returning to Nantian, the ground was affected by cold air, rainy weather, low daily average temperature, and the whole lower level blew north to northeast wind; With the influence of cold air weakened, the ground turned to be controlled by low trough, the southwest wind speed in the lower layer increased, the warm and humid airflow quickly counterattacked, and the temperature rose sharply, mainly cloudy to sunny weather.