Abstract:Utilizing upper air, surface data and dual polarization weather radar data, a hailstorm and short time severe rainfall weather occurred in the southeast coast of Fujian in 21-22 December 2016 is analyzed. The results show that the hailstorm in the afternoon 21 December is induced by the southwest warm advection forcing sector severe convection. The short time severe rainfall at night is the baroclinic frontogenesis severe convection. We analyze the hail phase state evolution based on the dual polarization weather radar products. The obvious hail features (ZDR≤0, echo intensity ≥55 dBz) appear around 0℃ level height firstly, then develop upward and downward. The TBSS (three body scattering spike) occurs at high level. But because the level of the wet bulb temperature zero (WBZ) is the same as the level of dry bulb temperature zero (DBZ), the melting level of hail is thick. In the afternoon the surface temperature is above 20℃. During the falling process of hails, the values of differential reflectivity (ZDR) and differential phase shift (KDP) change from negative to positive, which shows that the hails melt into big raindrops or outsourcing water film hails. The value ZDR changes from negative extreme to positive extreme and correlation coefficient (CC) is smaller than 0.7 where the area TBSS of echo intensity is 15-20 dBz, which are the characteristics of non meteorological echoes. ZDR and KDP of short time severe rainfall increase with the intensity of reflectivity, and the value of CC is above 0.97, which indicate that a large amount of relatively large sized raindrops are the main cause for this short time severe rainfall.