Abstract:In order to improve the understanding of precipitation characteristics of hailstorm in the Tibetan Plateau, based on the raindrop size distribution data observed by DSG5 disdrometer, radar reflectivity, FY-4A satellite and minutely precipitation data, etc., the precipitation microphysical characteristics of the hailstorm that occurred in Lhasa on 23 July 2020 is analyzed. The results show that there were some slightly differences at the time of beginning and end of the hailstorm, precipitation peak and total precipitation between rain gauge and DSG5 disdrometer although the minutely precipitation amounts of the two were similar. The fitted curves of the average spectrum distribution of raindrops and hailstones were monotonously decreasing. The raindrop size spectrum conformed to Γ distribution and the hail size spectrum accorded with M-P distribution. In the early stage of hail process, the precipitation particles were mostly small, which was mainly caused by the evaporation of the raindrops. In the later stage, the spectral width of precipitation particles became wider, the collision and fragmentation of the particles and the melting of graupel particles produced a large number of small raindrops, leading to a sharp increase in the number of particle concentration. The significant increase of number concentration and the widening of the droplet spectrum in this stage were the reason for the increased rainfall. The number concentration of hailstones only accounted for 1.6% of the total number concentration of precipitation particles, while the hailstones were the major contributors of the surface total precipitation. The empirical formula for the average terminal falling velocity and the diameter of the hails was fitted based on the observation.