Why is the temperature in Shanghai so high this year?

According to the meteorological data of previous years, we can see that Shanghai should be at the end of the rainy season in early July, and it should have rained for some time before. This is mainly due to the fact that during this period, the intensity of warm and humid air flow from the southern sea area and cold air mass from the north are similar in Jianghuai area, and the long-term sawing has formed a large-scale frontal rainfall weather process.

Although the arrival and end time of the rainy season in previous years are different, and the scope of influence is also large and small, it still presents a very obvious law on the whole. However, this year's situation is very different. On the one hand, this year, the western Pacific subtropical high has a fierce impact and the transfer and development momentum is fierce. Many areas along the southeast coast and east coast of China have been explored by it.

On the other hand, the North Africa-Iran high and the South Asia high are also severe this year. Due to the severe high temperature in South Asia, West Asia and North Africa in the early stage, it provided a good and rich heat source for the formation, development, maintenance and northward uplift of these two high pressures. In the process of moving, the two high pressures meet together, resulting in a "coupling effect", which makes the Qinghai-Tibet Plateau, Xinjiang and other regions of China prematurely affected by a large-scale downflow, resulting in persistence.