Radar Observation and Numerical Model Simulation of A Hail Storm Event of March 2014 in Eastern China

In the late afternoon of March 19, 2014, a severe hail storm swept through eastern-central Zhejiang Province, China, producing golf-ball sized hails that covered up the ground. Hail, strong winds and lightning lasted more than one hour when the storm passed Taizhou City. The life cycle of this hail event was well captured by the operational WSR-98D radars. In this study, the structure and evolution of the hail storm are first analyzed using the radar data while the environmental conditions are also documented. Numerical simulations are then produced using the Advanced Regional Prediction System (ARPS). The simulation using the Milbrandt-Yau three-moment microphysics scheme is able to reproduce the observed hail storm quite well, including the direction and speed of the storm propagation and the structure of the hail-bear regions of large reflectivity. Bounded weak echo and suspended overhang regions are also simulated. Based on the three predicted moments of hail, including its total number concentration, the number of hail stones falling to the ground over the life of storm for different hail size thresholds are estimated. The results indicate certain prediction skills of ARPS with the three-moment microphysics scheme. Diagnostic calculations are further performed to identify the main processes responsible for the hail growth.