SAL定量降水预报检验方法的解释与应用

The Explanation and Application of SAL Quantitative Verification for Precipitation Forecasts

引入德国定量降水预报检验SAL方法,以2009年6月29日降水(长江中下游2009年入梅首场降水)为例,对AREM、T639、T213、JAPAN模式0～24h降水预报的SAL检验进行剖析,与SAL方法原理介绍相结合,全面而详细地对SAL检验方法进行阐释,通过对2009年三次大范围强降水的检验,分析和总结SAL方法在降水预报检验中的应用。结果表明:1)SAL检验方法是对某一天降水的预报效果进行检验的方法,它可对雨带的预报从强度(A)、位置(L)、结构(S)三方面进行评估。2)SAL检验结果中,对降水预报效果指示意义最大的为L值,L值越小,预报效果好的可能性越大,A值其次,S值再次。3)SAL值只在针对同一个降水实况的条件下具有可比性,不同降水日,因作为检验参考系的实况不同,其S、A、L值不具可比性。

The SAL quantitative verification method for precipitation forecast is introduced from Germany. The SAL verifications for the 0-24h rain prediction of AREM, T639, T213, JAPAN models are analysed on the first event of rain in Meiyu period occurred on 29 June 2009 in the middle-lower reaches of Yangtze River. The SAL verification method and theory are explained in detail. The application of SAL for precipitation forecast are analysed and summarized with verification of the three events of heavy rain in 2009. The conclusions are as following： 1） SAL evaluation method can verify the rainbelt prediction effect from amplitude, location and structure aspects. 2） For SAL evaluation method, the value L has the most important indicative function, the smaller value of L often means the higher possibility of good rain prediction effect, the value A is in the next place, and the value S has a relatively small indicative function. 3） SAL evaluation results may be comparable only if the predictions correspond the same observation, otherwise the references are different, so the comparison is not meaningful.