Abstract:Hailstorms occurred in several areas of Shandong from afternoon to night on 1 June 2020. Using data of satellite, radar, and lightning detection system, the characteristics of lightning and radar parameters in the hailstorms are analyzed in detail. The results show that the major differences of the hailstorms in the northern and central Shandong Province are that the convective intensity of the hailstorm in the central Shandong Province is stronger than that in the northern part, and the ratio of positive CG (cloud-to-ground) to total CG lightning and the average current intensity of positive CG lightning in the central Shandong Province are obviously higher than those in the northern part. The common features of the two hailstorms are that the proportion of positive CG lightning is higher at the initial stage, and the percentage of IC (intracloud) lightning with respective to total lightning (including IC lightning and CG lightning) at the developing stage is higher than that at other stages. The lightning frequency, for both total lightning and IC lightning, increases sharply before hail is observed, their peak values are 6-18 min in advance of the occurrence of hailstones on the ground, and IC lightning is more active. After the hailstones land on surface, the frequency of IC lightning decreases rapidly, and the proportion of CG lightning to total lightning increases, even exceeding 50%. The lightning activities of hailstorms all occur in the cloud area where the cloud top temperature is below -50 ℃, and tend to cluster in the area of cloud top temperature below -60 ℃. The lightning occurs mostly in strong convective areas with the reflectivity above 30 dBZ. The dense IC lightning corresponds to the strong convective area, where the vertical velocity in the cloud is very high. The spatial distribution of negative CG lightning is remarkably consistent with the area with KDP>0.5 (°)·km-1 and ZDR>2.0 dB, indicating that negative CG lightning is closely related to the strong rainfall area. The high ZDR and low Cc in the echo vault of hailstorm are good indications for the strong updraft area. The areas with high ZH, low Cc, and low ZDR correspond to the areas with hailstones. The location of lightning corresponds well to the areas with large ice particles such as graupel, wet snow, hail, and dry snow. The volume with ZDR≥1.0 dB, the volume with ZH≥30 dBZ, and the ice water content of ZH≥30 dBZ above 0 ℃ are basically consistent with the evolution trend of the total lightning frequency, and the Pearson correlation coefficients between them and the total lightning frequency are 0.756, 0.780, and 0.710, respectively. It is further confirmed that large ice particles play a leading role in the electrification of thunderstorms.