Based on NCEP ( 1 °×1 °) FNL data and various frequently-observed data as well as the synoptic analysis method , two extreme local heavy rainstorm processes on July 28 ( Process 1) and August 5 ( Process 2) during main rainy season in 2023 in main urban area of Kunming are compared and analyzed . The results are as follows . Process 1 was weaker than Process 2 in terms of precipitation intensity , precipitation amount , severe precipitation range , and convective environment. The major impact systems of Process 1 were the shear line , the tropical depression over the Indian Peninsula , and the South China Sea Typhoon Doksuri , while Process 2 was influenced by the southerly airflow in the southwest periphery of the continental high-pressure system , the tropical depression in the Indian Peninsula and Indochina Peninsula , and the South China Sea Typhoon Khanun . The average radial velocity shows that four volume scans near the maximum hourly rainfall stations during the two processes experienced weak-to-moderate intensity mesocyclones , which suggests the formation of supercell storms leading to the generation of severe rainfall intensity. The main radar echoes evolution feature of Process 1 was the continuous generation of convective cell storms near the shear line , with obvious backward propagation characteristics , forming NW-SE block-shaped mixed echoes slowly moving southwest. By contrast , Process 2 was featured with the formation of block-shaped mixed echoes under the control of southward airflow in the periphery of the continental high pressure , with low wind speed and obvious backward propagation . Moreover , the block-shaped mixed echoes were not so active . The findings of this research can deepen the understanding of such processes and provide references for the local heavy rainstorm forecasting in urban area of Kunming City.