Abstract:A rare left-moving supercell generated by storm splitting occurred in central and northern Jiangxi Province from 14:00 BT to 18:00 BT 10 May 2021. Using dual-polarization radar data from the Ji’an CINRAD/SC radar, upper-air and surface observations and ERA5 reanalysis data, this paper analyzes the environmental conditions, structural characteristics, and dynamic mechanisms of this event. The results show that the left-moving supercell was generated in an environment with high convective available potential energy (>3000 J·kg-1) and strong 0-6 km vertical wind shear (>20 m·s-1). The vertical wind shear vector of 3.0-4.9 km exhibited counterclockwise rotation with height, generating significant negative horizontal vorticity, which was a key factor for the selective intensification of the left-moving supercell. During its mature stage, the storm displayed a “dual-vortex” structure at mid-to-upper levels, with a mesoanticyclone located in the leading (northern) sector corresponding to a strong updraft, and a mesocyclone in the trailing (southern) sector associated with the forward-flank downdraft (FFD). Its overall appearance was approximately mirror-symmetrical to the structure of classic right-moving supercell. Dual-polarization parameters demonstrate that the large differential reflectivity factor (ZDR) zone in the lower levels was related to particle sorting under strong vertical wind shear, while the ZDR ring and ZDR column at mid-levels indicated strong rotation and updraft within the meso-anticyclone, respectively. The formation of the mesoanticyclone was attributed to the tilting of negative horizontal vorticity into negative vertical vorticity by the robust updraft. The leftward motion of the storm was closely related to the location of FFD and the Magnus effect resulting from the pressure gradient force induced by the asymmetry between the northern and southern vortices. This study provides a valuable case for understanding the development, structure, and microphysical characteristics of left-moving supercells in China.