The squall line weather is seriously damaged.

Strong convective weather such as lightning, short-term gale, local hail and short-term precipitation occurred in Anyang, Hebi, Puyang, Xinxiang, Jiaozuo, Jiyuan, Zhengzhou, Kaifeng and Shangqiu. Among them, from 3 15: 46 to 23: 00, strong squall weather occurred in Zhengzhou, Kaifeng and Shangqiu. The length of the squall line is about 140 km, and it moves rapidly to the southeast at the speed of 50~60 km per hour. Subsequently, the squall line spread to northern Anhui and Heze, Shandong. According to statistics, thunderstorms occurred in more than 40 counties and cities in the province, and short-term northerly winds above17m/s (level 7) occurred in 9 counties and cities, among which the maximum wind speed in Shangqiu yongcheng city reached 29m/s (1 1 level) at 22: 42, which was/kloc-.

The reason why Shangqiu area is so seriously affected is a rare squall line weather phenomenon. The so-called "squall line" is a narrow cloud band formed by many thunderstorm cell, which contains huge energy and is incompatible with the external weather system. At the intersection of squall lines, the wind direction turns sharply, the wind speed increases sharply, the air pressure rises sharply, and the temperature drops sharply, usually accompanied by violent weather processes such as lightning, rainstorm, gale and hail. "This weather phenomenon has the characteristics of short formation time, fast development and fast movement, and it is difficult to forecast."

The squall line is caused by the interaction between the cold vortex at high altitude and the radiation warming of the clear sky near the ground. According to the analysis of meteorological observatory experts, the cause of this squall line weather process is the existence of the northeast high-altitude cold vortex, and the interaction between the southwest cold air of the high-altitude cold vortex and the radiation warming of the near-surface solar clear sky triggered the squall line in the north and east of Henan Province. Qiao Lin, chief forecaster of the Central Meteorological Observatory, said in an interview that the main difference between this weather process and the usual convective weather is that it is stronger and stronger. It is not a convective cell, but a number of convective cells connected in series, distributed in a strip shape, forming a squall line. However, there will be interaction between a series of convective cells. The downward flow of many thunderstorm cell will excite stronger convective cells at the front. Convective cells actually move in parallel direction, and new convective cells appear in front. That is to say, while moving, new convection cells are excited and lined up.