Abstract:Based on several rainstorm processes of landed typhoons in 2013-2015 and statistics, we propose a real time correction method for typhoon rainstorm forecast (also called ensemble member optimization method) using ECMWF precipitation and typhoon track ensemble forecasts and operational positioning of National Meteorological Certre (NMC) for the operational track forecast. The results show that ensemble statistic precipitation products are improved significantly by using the ensemble member optimization method, and the improved products give better performances than the ECMWF deterministic forecasts. Improvements of ensemble statistic products for short range forecast are more significant than medium range forecast, and that for extra torrential rain forecast are more significant than torrential and heavy rain forecast. Moreover, Fuse Matching average (FM) product is proposed in this paper, based on the characteristics and principles of Probability Matching average (PM) and fusing products. The results also show that the PM products with 10 to 15 optimal selected members give the best performance for 36 h forecast, while the threat scores of PM products can be promoted by 10% approximately for extra torrential rain forecasts. For 60 h and 84 h extra torrential rain forecasts, the threat scores of FM products can be promoted by above 20%, compared with the ECMWF deterministic forecasts.