2013年华中区域中尺度业务数值预报的客观检验

Objective verification on the operational numerical prediction system in central China in 2013

应用国家气象中心模式检验方法,对华中区域中尺度业务数值预报模式WRF和中国气象局下发的GRAPES模式2013年1—12月的预报产品(包括降水、2 m温度场、850 hPa温度场、850 hPa风场和500 hPa位势高度场预报)进行统计检验。检验结果表明:所有要素24 h预报均优于48 h;对于晴雨预报,GRAPES模式TS评分高于WRF,但随着降水量级增大,WRF的TS评分基本都高于GRAPES,同时WRF降水预报范围明显偏大;分析2 m温度场的均方根误差及预报准确率发现,WRF的2 m温度场预报优于GRAPES,且暖季预报优于冷季;形势场要素分析表明,WRF对850 hPa温度场和风场预报具有相当大的优势,全年误差变化较稳定,而对500hPa位势高度场的预报误差存在一定的季节性特征,即夏半年WRF高度场预报优于冬半年,GRAPES模式则相反。总体上,华中区域中尺度业务数值模式产品对天气预报具有一定的参考价值。

Forecast products, including rainfall, 2 m-temperature, temperature at 850 hPa, wind at 850 hPa and geopotential height at 500 hPa from WRF, which is a operational numerical model in central China, and GRAPES, which is the operational numerical model in China, from January to December of 2013, are examined using operational statistical verification methods. Results show that the prediction of all 24-hour forecast variables is better than those of the 48-hour. For rain/no-rain forecast, the TS score of GRAPES model was higher than that of WRF model;however, as precipitation intensity increases, the TS scores of WRF model become almost always higher than that of GRAPES. At the same time, the precipitation prediction range of WRF is significantly greater than the observed rainfall. The verification on 2 m-tem-perature found that the prediction by the WRF is better than that of GRAPES, and it is better in warm season than in cold season. The analysis of the atmospheric circulation field shows that the WRF model has a considerable advantage in the temperature and wind fields at 850 hPa. But there are some seasonal characteristics in the forecast errors of 500 hPa height field of WRF. The forecast of geopotential height by WRF is better for the summer half year than for the winter half year;the opposite is true for GRAPES model. In general, the operational numerical model in central China has some referential value for the weather forecast.