Abstract:Using the detection data of dual Doppler weather radar (Changzhou and Taizhou station), combined with the conventional observation data and the ERA5 reanalysis data, this study comprehensively analyzes the synoptic situation, the evolution characteristics of reflectivity and the 3D flow field information retrieved by dual Doppler radar during a severe convective weather process on July 6, 2019. The structure of the hail cloud is analyzed based on the grid point flow field retrieved from the radial velocity data of the dual Doppler radar and combining with the reflectivity characteristics. The results shows that in the process of severe convective weather, Jiangsu Province is affected by the high-altitude cold vortex. Under the conditions of high-altitude cold troughs, high-altitude jet stream, low-level shear lines and ground convergence lines, an unstable stratification with upper dry cooling and lower part warm and humid has been formed. During this weather process, the hail cloud not only has the typical radar reflectivity characteristics of strong convection monomer, but also has the obvious S-shaped horizontal flow field structure at the strong echo center in the middle layer of the hail cloud. The lower layer of the hail cloud has a horizontal flow field with obvious convergence and rotating configuration. The deep zero line structure is a typical characteristic of hail formation.