Applications of ensemble statistic-integrating method to short-range torrential rain forecast in Hubei province

Based on the precipitation forecast data from 51 members of the ECMWF Global Ensemble Prediction from November 2013 to November 2014 and the daily precipitation observation data at 78 national meteorological stations in Hubei province, the skill of precipitation forecast for 10 kinds of ensemble statistic products including ensemble mean, quantiles, probability-matching mean and mode value was evaluated respectively in different prediction regions in Hubei province. Moreover, according to the principle of selecting ensemble statistic which TS score was the highest at different precipitation levels, the best ensemble statistic-integrating scheme suitable for precipitation prediction in Hubei province was designed, and then the application performance of this method was tested in the precipitation forecast of Hubei province from June to August in 2015 and 2016. The results were showed as follows. When the ensemble statistic-integrating method was applied to the precipitation forecast in Hubei province, its scheme should be changed with the change of prediction region.The improved ECMWF ensemble statistic-integrating scheme has improved the TS scores of precipitation forecast for heavy rain and above within 72 hours in Hubei province, and its false rate and fail rate have been reduced overall.Compared to ECMWF deterministic forecast, the precipitation forecast results of ensemble statistic-integrating products are all better than those of deterministic forecast products in Hubei province within 24 hours, and the accuracy of torrential rain forecast within 72 hours in Hubei province is higher.