A preliminary analysis was conducted on the causes of an extreme strong wind that occurred on July 26, 2022 in the initial stage of a squall line in central and southern Jiangsu Province, using multi-source meteorological observation data such as conventional weather maps, Doppler weather radar, wind profile radar and automatic weather stations, as well as on-site investigations. The results show that this process occurred under the background of cold vortex weather, with the eastward movement of the forward leaning trough and the weakening of the subtropical high pressure southward retreat. The significant temperature differences between the upper and lower layers, the abnormally dry layer structure in the middle layer, the large direct decrease rate of environmental temperature, and the large accumulation of unstable energy in the early stage provided a favorable convective environment for the occurrence of thunderstorms, strong winds, and strong convection. With the invasion of cold air in the near surface layer, the range of low-level jets expands and moves downwards, and the vertical wind shear in the boundary layer increases sharply. After the convective echo enters Jiangsu, the initial convection was triggered by the surface small-scale convergence line, and it strengthens into organized squall lines in Yangzhou-Zhenjiang. There is a strong convergence and rotation at the top of the squall line, with extreme winds of level 12 located in the warm and humid upwelling area in front of the core area of the supercell storm. The wind direction points from the warm area to the strong echo, and the mesocyclone shows strong rotation and upward stretching, accompanied by Tornado Vortex Signature (TVS). A large amount of water vapor and energy are also input into the convective system with the incoming flow. The vertical circulation tilt and stretching vorticity of the storm further increase, indicating that the squall line will develop strongly.

Based on the groundbased 3D lightning detection network (3D LDN) data in Dalian and Qingdao areas, the detection efficiency of FY-4A lightning mapping imager (LMI) in the Yellow sea and Bohai sea area was evaluated. It was found that from the four severe convective weather processes in Dalian area in 2019, most of the lightning pulses occurred within radar echoes intensity greater than 30 dBZ, and the corresponding cloud top height was about 9 km, the number of groups detected by FY4A LMI was fewer than that of the pulses presented by groundbased 3D LDN, the average ratio was 0.2, ranging from 0.15 to 0.26. From the five severe convective weather processes in Qingdao area in 2019, the number of groups detected by FY4A LMI was also fewer than that of the pulses presented by groundbased 3D LDN, the average ratio was 0.34, ranging from 0.27 to 0.4. Generally, the lightning pulses location detected by FY-4A LMI was consistent with the lightning pulses presented by groundbased 3D LDN in Qingdao area, which located in strong echo area. However, the detection efficiency of FY4A LMI in the Yellow Sea and Bohai Sea area was lower.