基于模式相对湿度的降水概率预报方法研究  

A precipitation probability forecast method based on the relative humidity of NWP

作　　者：储海[1] 漆梁波[1] 

机构地区：[1]上海中心气象台,上海200030

出　　处：《气象与环境学报》2017年第1期44-50,共7页Journal of Meteorology and Environment

基　　金：中国气象局气象关键技术集成与应用项目"格点化最优集成及极端降水预报释用技术"(CMAGJ2015M22)资助

摘　　要：本文采用EC数值模式预报结果与历史观测资料结合的方法,建立了一种基于模式确定性相对湿度预报制作降水概率产品的方法。通过对2012—2013年华东地区EC细网格模式大气相对湿度预报进行分类,将不同层次和不同湿度等级的大气进行分类采样,并统计各类别对应的历史降水概率,分析模式相对湿度与实际降水概率的分布特征,进而根据当前模式预报的相对湿度预报降水概率。采用ETS评分、Brier评分、可信度对比及个例分析方法检验2013年7月至2014年5月降水预报试验效果,结果表明:本文建立基于模式相对湿度的降水概率预报方法可较好的反映未来降水的分布,对天气尺度雨带的预报效果优于对流性降水;与EC模式相比,可有效降低空报现象;与传统集合概率预报相比,本文建立的降水预报方法可更好地反映实际降水的发生概率,降水概率产品能较好的指示降水发生的位置和可能性,具有较好的实际参考价值。By means of combining NWP outputs and historical observation data, a precipitation probability forecast method based on relative humidity is established. Fine-grid forecasting results of relative humidity from EC model during the year 2012 and 2013 in eastern China are classified into different vertical layers and different moisture grads. The historical precipitation probability corresponding to these layers and grads are analyzed to find out a relationship between the forecast humility and precipitation probability. The relative humidity predicted by the current forecast model is then used to estimate the future precipitation probability. Different methods such as ETS score, Brier score, reliability map and case study are used to verify the forecasting effects of precipitation from July 2013 to May 2014. The results show that the method can produce fairly good distribution of future precipitation. The effects of synoptic-scale rain band appear to be better than those of convective precipitation. The false forecasting rate is effectively reduced compared with EC model results. The precipitation production can be used to specify the location and probability of the precipitation and provides a better reference value.

关 键 词：EC模式 降水概率 确定性预报 相对湿度 历史统计 

分 类 号：P457.6[天文地球—大气科学及气象学]