Abstract:The spatial and temporal characteristics of 16 hail events are analyzed by means of radiosonde data from three nearby stations and conventional data of Rizhao Station from 1960 to 2000. Based on the synoptic weather classification, hailing factors are calculated by using the numerical cumulus model. The historical hailing factor case database is established by using the hailing factors and single station data, and a actual case database by using historical observation data. A method for forecasting the amount, time and location of hails in Rizhao, Shangdong Province is developed by means of the distance analog method.