Abstract:
Using ERA5 reanalysis data, combined with ground data, satellite cloud imagery and radar products, the characteristics of two plateau vorticity movements during July 22—26, 2024 were analyzed. The results show that the two vortices exhibited generally shallow structures and were located within divergence zones near the ridge line of a high-pressure system. In their initial development stage, they were associated with high-value areas of pseudo-equivalent potential temperature at 400 hPa, while their maintenance and development were related to thermal convection and strong upward motion in the middle and upper levels. The vortex cloud systems moved eastward and southward into the Western Sichuan Plateau, where they continued to develop, serving as the primary systems responsible for the heavy precipitation. The two vortices were characterized by large-scale stratiform cloud echoes, moved slowly, and maintained nearly stationary precipitation echoes. Strong echo centers developed echo walls in the vertical direction, leading to intense localized rainfall.