Abstract:
To investigate the mobility of the Southwest China Vortex (SWV) and its associated rainstorm regions, this study examined 25 SWV-related rainstorm events that affected Chongqing during 2019–2023. A dynamic compositing method that tracks the movement of the vortex center was employed to analyze the circulation structure of the SWV and the distribution of heavy rainfall relative to the vortex center. The conclusions are as follows: SWV rainstorms can be categorized into three types: southeastern, eastern, and multi-quadrant types. The distribution of heavy rainfall for each SWV type is closely related to the position of the upper-level jet, the intensity and meridional extent of the trough, the exit region of low-level jets, and the distribution of warm-air and cold-air advection, while the thermodynamic and dynamic characteristics exhibit distinct similarities and differences. The southeastern type is influenced by the short-lived SWV with weaker upward motion, shallow vertical development, and a pronounced northwestward tilt. The eastern type involves the long-lived, intense SWV with deeper vertical development and a low-level northwestward tilt. The multi-quadrant type is influenced by the SWV with sustained cold-air intrusion from the rear and strong uplift movement. The configuration features symmetric winds in the front and rear, pronounced cold- and warm-air convergence, the deepest vertical development among the three types, and a low-level northward tilt.