Abstract:The mesoscale WRF model was used to simulate a heavy rainfall process in Zhejiang, Fujian and Jiangxi Province on June 19, 2010. The characteristics of precipitation budget and the thermal effect of ice clouds in this region were analyzed with the simulation data. According to the three factors of local water vapor/heat change, water vapor/heat convergence and cloud hydrometeor convergence, precipitation can be divided into eight categories. When local atmosphere dries and warms, water vapor convergence and heat divergence, and cloud hydrometeor convergence, precipitation intensity (rain intensity) is the strongest, while local water vapor becomes wet and atmosphere cools, water vapor convergence and heat divergence, and cloud condensate convergence, the rainfall coverage is the largest. The thermal effect of ice cloud includes radiation and latent heat. The comparison between control experiment and sensitivity experiments shows that the radiative effect of ice cloud decreases rainfall, while the latent heat of ice cloud enhances rainfall. The comparation analysis of heat budget shows that the decreasing of radiative cooling caused by ice cloud radiatiive effect increases with height in the middle and lower troposphere, which reduces atmospheric in stability and rainfall; while the increasing of latent heat caused by ice cloud latent heat decreases with height in the middle and upper troposphere, which enhances atmospheric instability and rainfall.