国家级强对流天气分类预报检验分析

摘要

提预报产品的客观检验是记录、考量各种预报业务质量，促进预报水平提高的重要手段，也是整个天气预报过程中的重要环节。本文采用“点对面”Threat Score（TS）、漏报率、空报率等客观指标首次对2010—2015年4—9月国家级强对流天气预报中雷暴、短时强降雨以及雷暴大风和冰雹等分类预报进行了检验。同时，本文也对强对流天气落区分类预报客观检验存在的问题以及未来发展进行了讨论。检验结果表明：过去6年间，6～24 h时效预报，雷暴TS评分为0．22～0．34，短时强降水为0．18～0．24，雷暴大风和冰雹为0．01～0．07；48、72 h时效预报，雷暴TS评分为0．30～0．40，强对流天气TS评分为0．16～0．23，除雷暴预报TS评分在2012—2013年有所回落外，其他类别的强对流天气预报总体上TS评分呈上升趋势，雷暴大风和冰雹预报评分明显低于其他两个类别。雷暴空报率是漏报率的2～3倍，短时强降水漏报率与空报率接近，雷暴大风和冰雹天气漏报率和空报率都在0．8以上。与美国风暴预报中心（SPC）2000—2010年定期发布的1 d对流展望产品检验结果比较，强天气预报中心雷暴和短时强降水落区预报TS评分较高，雷暴大风和冰雹评分较低。典型个例预报检验结果表明，系统性大范围的风雹天气可预报性较强，评分要显著高于平均预报水平；对于非过程性的、分散的风雹天气，预报难度大，TS评分低。%Anstract:The objective assessment of forecast is an important part in the whole weather forecasting cycle. Based on the assessment,qualities of different operational forecasts can be noted and considered,so enhan-cing the level of forecast.The verification of national severe convective weather categorical forecasts from April to September during 2010-2015 is displayed by adopting the objective indices of the “point-to-area”thret score (TS),the false alarm rate (FAR)and the missing alarm rate (MAR)in this paper.At the same time,analysis is carried out for different time interval forecasts of the annual mean verification index (mainly is from April to September of the year).Furthermore,the problems existing in the verification of severe convective weather categorical forecasts and its development in the future are also discussed.Over the past six years,in addition to the decrease of thunderstorm forecast TS during 2012-2013,there was a rising trend for TS of severe convective weather forecasting.For the 6-24 h forecasts,the TS of thunder-storm was 0.22-0.34,the TS of the short-time heavy rain was 0.18-0.24,the TS of thunderstorm gale and hailstone was 0.01-0.07;for the 48-72 h forecasts,the TS of thunderstorm was 0.30-0.40,the TS of severe convective weather was 0.16-0.23.The TS of thunderstorm gale and hailstone was lower than that of the other two kinds of severe convective weather.The FAR of thunderstorm was twice as large as MAR of thunderstorm;the FAR of short-time heavy rain was close to its MAR,while the FAR and MAR of thunderstorm gale and hailstone were all larger than 0 .8 .Compared with the TSs of similar products in Storm Prediction Center (SPC)of USA,the TSs of thunderstorm and short-time heavy rain are higher than that of SPC and the TS of thunderstorm gale and hailstone is lower than that of SPC.Veri-fication of typical case forecasting shows that the TS of systemic and widespread thunderstorm gale and hailstone is higher than that in other situations.The reason is that the predictability of systemic and wide-spread thunderstorm gale and hailstone is higher.