Abstract:In this paper, 28 cases of afternoon thunderstorm in Hangzhou from June to August in 2013-2018 were selected for research. There are four main paths (from more to less frequent): northwest moving to eastward, southwest to northeast, southeast to northward, and locally generated in Hangzhou. From the evolution of dual-polarization radar echo, three key areas of thunderstorm can be seen, including northwest, southwest and northeast. Three types of thunderstorm conceptual model are: cold advection forcing category, warm advection forcing category and quasi-barotropic category, of which, the quasi-positive pressure type in Hangzhou Area is mostly combined with boundary layer convergence line and east wind belt system. The near-surface meso-scale convergence line is the lifting trigger mechanism, which is related to boundary weak cold air invasion, subtropical high control, land and sea distribution, topography and other factors. The characteristics of the T-lnp diagram are: a moderate intensity CAPE, dry air in mid and high level, a shallow wet layer in the lower layer, the lapse rate of atmospheric temperature in the lower atmosphere, close to dry adiabatic, and an inverted “V” shape, shown by the temperature and dew point profile under the wet layer. The average values of CAPE and DCAPE are above 1 〖KG-*5〗000 J·kg-1. The average temperature-dewpoint difference of middle layer and the maximum temperature-dewpoint difference of single layer can well represent the dry air of middle layer. In summer, thunderstorms usually occur under the condition of weak vertical wind shear. The wind index has some indication.