Study on the atmospheric environment and radar echo characteristics of 18 hail events in JinHua

Using micaps data, Doppler radar data and mesoscale meteorological data, etc, eighteen hail events occurred in Jinhua area during 9 years were analyzed. The results showed that:(1) the weather types of hail in Jinhua can be classified into two types, i.e., westerly trough type and subtropical high type. The annual high occurrence time is concentrated in spring and summer, while the diurnal peak is concentrated in the afternoon. (2) The convective available potential energy and wind vertical shear are two important factors for hail generation. Hail in summer mostly occurred in high energy and weak wind shear environment. Hail in spring mostly occurred in the low energy and strong wind shear environment. Large hail occurred in high energy environment, especially in the high energy and medium shear environment. (3) The moisture content of the atmosphere before the occurrence of hail is very high. The average value of PWV can reach 40.8 mm, and level of wet blub zero is appropriate. (4) The lifetime of hail is more than 1 hour, and the maximum radar base reflectivity is above 60 dBz. The distribution of storm top height of hailstorm cloud is consistent with that of echo top height, and has an obvious seasonal variation. (5) VIL (storm cell) of hail storm increases first and then decreases, with at least one jump in the middle. The sudden drop time after the maximum value is basically the same as the hail time. Strong weather probability (SWP) product is ahead 12~160 min of hail.