基于CMPAS的“韦帕”台风过程降水真实性评估

Assessment of the Authenticity of Precipitation During the“Wipha”Typhoon Process Based on CMPAS

文章基于国家气象信息中心下发的实况分析降水融合产品(CMPAS),采用经过质量控制的站点降水作为真值,采用多种误差指标和评分指标,评估了融合产品对“韦帕”台风过程降水的反演能力。综合评估结果表明,该实况融合产品对降水的空间分布、时间分布和大值区范围有较好的刻画能力,但对于极值大小和区域的刻画不太精准,同时表现出误差随降水量增加而增大的趋势,所以该产品可以用于较小量级降水的落区预报以及站点降水极值出现时间的预报,但是对于强降水过程的预报需慎用。

Based on the CMPAS issued by the National Meteorological Information Center,this paper evaluates the retrieval ability of the merge product during the“Weipa”typhoon process,using the precipitation of the quality control stations as true value.The evaluation process uses a variety of error indicators and scoring indicators.The results show that:①The grid products generally reflect the actual rainfall distribution,but fail to accurately reflect the area where the precipitation extreme value is located,and the rainfall maximum area and the error maximum area basically coincide.②Almost all the scoring indicators showed a downward trend with the increase of rainfall magnitude,and the TS score and hit rate decreased most significantly.The rate of empty report was very high in all rainfall magnitude,and the comprehensive score of non-independent test was significantly higher than that of independent test.③The evaluation of the single station with the largest error shows that the grid value is generally smaller than the station value,and the deviation is the most obvious at the extreme value;The grid value normally reflects the time when the extreme precipitation occurs,which is consistent with the trend of the whole process.④According to the comprehensive evaluation results,the real-time merge product has a good ability to depict the spatial distribution,time distribution and large value range of precipitation,but it is not accurate to depict the size and area of extreme value,and shows the trend of error increasing with precipitation.Therefore,this product can be used to forecast the precipitation area of small magnitude and the occurrence time of precipitation extremes at stations,but it should be used with caution for the prediction of heavy precipitation processes.