Abstract:
The followings are the main characteristics of the performance of ECMWF ensemble forecasts during several strong precipitation processes in regions south of Yangtze River, Sichuan Basin and North China in 2013 flooding season. In regions south of Yangtze River and Sichuan Basin, some ensemble products, including probability matching, statistic fusing, maximum, 75% and 90% quantile products, show some positive skills in heavy rain and torrential rain forecasts, compared with the deterministic forecasts. Overall, statistic fusing and 90% quantile products show the best performance. In North China, consistent positive skills are found only in 90% quantile products. As a whole, the skill scores of medium-range forecasts are higher than the ones of short-range forecasts for above-mentioned products. In addition, the forecast skill scores of warm area heavy rain are higher (lower) than the ones of fontal heavy rain in Sichuan Basin (North China) for these products, statistically. Two new products, probability matching-fusing and fusing-probability matching, have been proposed in this paper, based on the characteristics and principles of probability matching and fusing products. The statistical results indicate that, the threat scores of fusing-probability matching are higher than fusing product on the rainstorm and heavy rainstorm forecasts.