Anyue, Sichuan Province was hit by extreme weather of strong wind and hail at night, and 20 people were slightly injured. What precautions should citizens take?

The northern branch trough gives cold air, the plateau trough moves eastward and gives southwest warm and humid air flow. The southwest vortex is formed by decompression in front of the trough and the shear line is formed in the basin. The rapid warming in the early stage has accumulated a lot of heat in the basin, and the energy of atmospheric instability is very sufficient. As long as the cold and warm collide, it will inevitably form a wide range of strong convective weather. ?

850 HPA 1 1 daily temperature anomaly shows obvious cold and warm boundaries and collision points. Not only in Sichuan basin, but also in Hebei, Henan and Shandong last night. Hail appeared in Handan and other places. However, the convection conditions in Sichuan basin are still relatively good.

Anyue's situation is really unexpected. In advance, we thought that it was difficult to have a downburst in the basin, because the convection in the basin was mainly at night, and the temperature was not as high as that in the day. However, in this process, the thunderstorm belt affected the western part of the basin in the evening after the western Sichuan Plateau went south. Around 8: 00, it continued to generate new cells in Neijiang area of Yibin, Zigong, and merged with the thunderstorm clouds in Ziyang, Deyang and Chengdu in the east of Longmen Mountain to form a linear convection system, which reached its peak at about 10 in Fushun area, Longchang, Anyue, and some cells crossed the top, especially the strong cells near Anyue, and then the cloud top collapsed rapidly. The descending airflow absorbs huge horizontal momentum in the descending process and moves forward quickly. When it reaches the ground, it can form a downburst and directly impact Anyue. We can see the obvious bow echo on the radar chart.

Since then, the system has weakened rapidly in the process of moving eastward, but it still has a considerable impact on the western part of Chongqing. It is suspected that gust front brought 8 ~ 10 gale to Dazubi Mountain in Tongnan, including the main city of Chongqing.

After the system moved into Chongqing, it continued to excite convection in the south of Chongqing, but the energy was not as good as before and no purple echo was excited. There are few hailstones witnessed in Chongqing. Then the system began to rotate and became the prototype of the cyclone, and continued eastward to form the Jianghuai cyclone.

This severe convective process is one of the most serious in Sichuan Basin in recent 20 years. The Anyue process is similar to the 1986 Rongchang wind and hail disaster, especially its short-term extreme rainfall intensity, which is rare in other parts of China. Of course, the peak of the strong wind formed by the downburst should be19,321Lingui strong convection, and the strong wind of 17 was recorded at Guilin National Station.