Season and causes of formation of quasi-stationary front in South China

The season and causes of the formation of the quasi-stationary front in South China are as follows:

The season when the quasi-stationary front in South China forms is spring, around April. Cause: The northwest Pacific subtropical high pressure has strengthened, and its westerly airflow has begun to approach the southern coastal areas of my country in the form of southerly winds. The southeast monsoon and the winter monsoon meet to form a front. Since the southeast monsoon and the northerly wind are evenly matched, the front swings along the coast of South China, forming a quasi-stationary front.

The South China quasi-stationary weather front (South China quasi-stationary weather front), also known as the Nanling stationary front, refers to the quasi-stationary front located in South my country and distributed in an east-west direction. When it is located in the northern part of the South China Sea, it is also called the South China Sea stationary front.

It is mostly caused by the weakening of cold air moving southward and the obstruction of the Nanling Mountains. It often appears in conjunction with the air shear line, with easterly winds on the north side and southwesterly winds on the south side. , with significant precipitation, is an important weather system affecting southern China.

The cloud system of the quasi-stationary front is mainly divided into two categories, and the corresponding weather phenomena are rain and no rain.

There are four main quasi-stationary fronts that affect my country, namely: Jianghuai quasi-stationary front, Kunming quasi-stationary front, South China quasi-stationary front, and Tianshan quasi-stationary front.

In the Jianghuai River Basin of my country, between June and July in early summer every year, the warm and moist airflow from the ocean reaches both sides of the Yangtze River. At this time, the cold air controlling the Jianghuai River Basin is still relatively strong, and it is difficult for it to retreat northward quickly. Warm and cold air masses confront each other in the middle and lower reaches of the Yangtze River and the Huaihe River Basin, and the stalemate forms a famous weather system - the Jianghuai quasi-stationary front.