Abstract:By using routine observation data, the climate characteristics of the hail in fo ur areas of Guangxi are analyzed. The circulation patterns that causes hail are c lassified to be three kinds: Huabei trough, east plateau trough, south branch troug h. By searching the forecast factors with physics meaning from numerical forecas t products, the potential forecast of hail is produced by using the discriminate analytical method and index accumulating method. The results show that the inde x accumulating method is better than the discriminate analytical method. Based o n the parameter estimation of numerical model output fields, different threshold s for different parameters are set up to produce the probability forecast of the falling area for the hail happened in Guangxi. Process forecast has some effect while the falling area forecast needs to be improved.