三种数值模式对四川省汛期降水预报性能的检验

The Precipitation Verification of Three Models during Rainy Season in Sichuan Province

应用国家基本观测站资料,基于MET系统的客观统计检验方法,针对24h降水分别评估SWCWARMS模式、GRAPES模式和ECMWF模式对2017~2019年5~10月四川地区汛期预报能力,得到如下几点结论:(1)SWCWARMS模式小到大暴雨降水范围大于实况,GRAPES模式小到暴雨降水范围大于实况、大暴雨多漏报,ECMWF模式小雨和中雨降水范围大于实况、大到大暴雨多漏报,三个模式无降水或微量降水均少于实况。(2)ECMWF模式对四川雨季小到大雨预报能力优于SWCWARMS和GRAPES模式,SWCWARMS模式在部分时次上暴雨和大暴雨预报优于ECMWF模式,GRAPES模式TS评分略偏低。(3)GRAPES模式在2018年秋季开始中雨及以上量级降水预报上改善大于SWCWARMS和ECMWF模式,SWCWARMS模式2019年空报较2017年和2018年显著降低;3个模式在小雨和中雨预报上不相上下,GRAPES模式优势在2019年大雨和暴雨预报上,ECMWF模式优势在2017年秋季和2018年初夏大雨预报上,SWCWARMS模式大雨和暴雨预报能力介于二者之间。(4)ECMWF和SWCWARMS模式川东预报优于川西,GRAPES模式川西预报优于川东;三个模式存在不同程度空报,川东地区空报略多于川西,其中ECMWF模式空报最多。

Using the Observation precipitation data and objective statistical verification method based on the MET system,the 24 h precipitation forecasting capabilities of the SWCWARMS model,GRAPES model and ECMWF model are verified in the Sichuan region during the rainy season(May to October)from 2017 to 2013.The main results are:(1)Precipitation forecasted by SWCWARMS model is greater than observation from light rain to rainstorm,Precipitation forecasted by GRAPES model is greater than observation from light rain to hard rain,rainstorm is often underreported,ECMWF model light rain and moderate rain is larger than the observation,from heavy rain to rainstorm are more underreporting.(2)ECMWF model is superior to SWCWARMS model and GRAPES model in predicting rainy season from light rain to heavy rain in Sichuan,Part of hard rain and rainstorm prediction by the SWCWARMS model is better than the ECMWF model,TS score of GRAPES model is slightly lower.(3)The GRAPES model improved more than the SWCWARMS and ECMWF model in the forecast of moderate rain and above in 2018,and the false prediction of the SWCWARMS model in 2019 decreased significantly compared with 2017 and 2018;the capability of 3 models are equal in light rain and moderate rain,GRAPES advantage on the forecast of heavy rain and rainstorm in 2019,the advantage of ECMWF is in the forecast of heavy rain in autumn 2017 and early summer of 2018,the ability of SWCWARMS to forecast heavy rain and rainstorm is between the two models.(4)The ECMWF and SWCWARMS model forecast in eastern Sichuan are superior to western Sichuan,and the GRAPES model forecast in western Sichuan is superior to eastern Sichuan.Among the three models,there are more false prediction in East Sichuan than in West Sichuan,and the ECMWF model has more false prediction than the others.