2011年长江中下游梅雨期强降水延伸期集合预报性能初探  

Performance Analysis on Extended-Range Ensemble Prediction over Middle and Lower Reaches of Yangtze River in Meiyu Period of 2011

作　　者：李勇 

机构地区：[1]国家气象中心,北京100081

出　　处：《气象》2016年第9期1114-1123,共10页Meteorological Monthly

基　　金：国家科技支撑项目(2015BAC03B04;2015BAC03B07);中国气象局预报员专项(CMAYBY2012-074)共同资助

摘　　要：针对2011年长江中下游旱涝转换时期的环流形势、强降雨期间的四次强降雨过程对欧洲中心集合预报进行了预报性能初步分析。结果表明：集合平均预报对延伸期预报时效内的大尺度环流调整具有较好的预报性能，预报提前时效可达10～15d。对强降水过程期间主要影响系统的预报在不同预报时效具有较好的稳定性。随着预报时效的临近，集合颅报各个成员对天气系统预报的发散度逐渐减小。长江中下游强降水的发生与低层850hPa较大的风速有密切关联，集合预报给出的延伸期预报时效内大风速出现的小概率预报信息是有意义的，可以为延伸期强降雨过程预报提供参考。Using ECMWF Ensemble data, the performances of ensemble forecasting about large scale circu lation and heavy rain processes in the mid-lower reaches of the Yangtze River during the drought and flood transition period in 2011 are examined. The results show that ensemble average forecasting has a good performance on the adjustments of large-scale circulation in the whole troposphere in extended-range period of validity. The forecasting period is up to 10-15 days. During different forecasting periods, ensemble average forecasting displays stability of forecasting the main affecting systems during the heavy rain processes. With the shortening of the forecasting period, the dispersion of various ensemble members to weather sys tems gradually decreases. The forecasting of individual ensemble member including ensemble average and control member has not obvious regularity in different period of validity. The forecast of a few ensemble members is in accord with the real weather condition about main impact systems during different forecas ting periods. Occurrence of low-level stronger winds is closely related to heavy rainfall in middower reaches of the Yangtze River. The small probability information of ensemble forecasting is meaningful in the extended-range forecasting period. It can provide a reference for extended-range heavy rainfall forecast.

关 键 词：环流调整 强降水过程 集合预报 检验 

分 类 号：P456[天文地球—大气科学及气象学]