Abstract:This study employs the high-resolution operational model CMA-MESO to simulate a convective cloud precipitation process in Shandong Province by using a double-moment microphysical scheme with/without hail. The mechanism of hail microphysical effect on convective cloud precipitation and the predictive ability of this model in forecasting hail cloud precipitation are comparatively analyzed. The results show that the CMA-MESO model can simulate this convective precipitation process well. Compared with observations, the squall line life cycle in the model results is similar to the observation, and the distribution and magnitude of precipitation are close to the observation, too. The average liquid water and ice water path of the control group (without hail) in the simulated area is larger than that of the experimental group (including hail). The rising speed of the convective core area in the experimental group slightly increases during convective development but decreases at other times. When hail occurs, the melting and heat absorption in the experimental group is stronger than in the control group. This might be due to the stronger falling speed of hail compared to that of other water condensates, which suppresses the development of convection during the falling process of hail. In addition, increasing the hail amount can affect convective precipitation. The proportion of moderate rain ［1-10 mm·(24 h)-1］ area to the total precipita-tion area in the experimental group decreases, while the proportion of heavy rain and above ［>10 mm·(24 h)-1］ area to the total precipitation area slightly increases. In terms of precipitation amount, with the increased hail, there is no significant change in the intensity of medium-to-light precipitation, but the intensity of heavy rain and above increases.