基于概率匹配的西南区域模式定量降水订正试验

摘要

利用2014-2015年5-10月地面观测降水资料和同时段的西南区域模式降水预报资料,基于概率匹配方法,采取分区及点对点匹配两种方案对2016年6-8月降水集中时段逐12h累积降水进行订正试验.结果表明:①订正后的模式预报相比订正前而言,平均(绝对)误差有所减小,降水落区的范围和平均强度与实况更加接近;②量级偏差越大,运用该方法的订正效果越好,夜间降水订正效果优于白天;③分区统计方案对模式系统性偏差的订正效果优于点对点方案,合理的区域划分增加统计样本量可以提高订正效果.%Using the precipitation observations and SWC-WARMS forecasts from May to October,from 2014 to 2015,based on the probability matching method,we analyze the characteristics of mean rain forecast deviation.An experiment is performed to correct the 12-hour cumulative precipitation forecast from June to August of 2016 by taking the division and point-to-point matching plans.The results show that:(1) After calibration,the mean (absolute) error reduces,and the rain area and average intensity are more similar to the observed.(2) The effectiveness of correction is more obvious with larger forecast deviation,and the method performs better at night than in the day time.(3) The division plan works better than the other one for the model systematic deviation;that is to say,a reasonable division to increase statistical samples can improve the effectiveness of correction.