Abstract:The WRF model is used to simulate the Meiyu front rainstorm process in the Jianghuai area on June 23, 2013, and the fine mesh data output from the model was used for diagnostic analysis. Results show that the configuration of surface Meiyu front, coupling of upper and lower jets, lower level convergence and upper level divergence, and short wave trough in middle troposphere are conducive to the occurrence and development of rainstorm. The rainstorm is mainly caused by the development, maintenance and merger of two mesoscale convective systems; The lower level convergence and upper level divergence provide the dynamic condition for the rainstorm. High temperature and humidity provide water vapor and thermal conditions for the rainstorm. The diagnostic analysis of water vapor and latent heat shows that the combination of the suction effect of the high-altitude trough and the latent heat feedback is manifested in two aspects. First, the water vapor is transported to the middle layer, so that the maximum condensation occurs in the middle layer, and the positive vorticity center of the lower layer is strengthened. The second is to deliver a steady stream of heat to the upper level, avoiding the accumulation of latent heat in the middle layer, which is conducive to the maintenance of unstable and rising movements, thus affecting the movement and development of mesoscale convective systems.