2013年西北太平洋台风路径集合预报

Ensemble forecasts of 2013's typhoon tracks over Northwestern Pacific

基于中国气象局、中国台湾气象局、日本气象厅和美国国家气象局等4个气象预报中心的台风预报资料,利用加权消除偏差集合方法对2013年发生在西北太平洋的31场台风进行了24 h、48 h和72 h集合预报,并对预报成果进行误差统计分析。结果表明:采用静态训练法的集合预报对训练期样本的选择较为敏感,整体误差波动较大;而采用动态训练法的集合预报整体误差随训练样本数的增加有减小的趋势,但当训练样本数达到40后预报误差趋于稳定。对比发现,在训练期中是否考虑双台风的影响对预报精度影响较大,去除双台风影响后,集合预报精度有明显的提高。经综合比较,就2013年台风而言,去除双台风影响、滑动训练样本为40的路径集合预报方案为推荐方案。

Based on forecast data obtained from the China Meteorological Administration,Taiwan Meteorological Center,Japan Meteorological Agency,and Joint Typhoon Warning Center of the USA,24-hour,48-hour,and72-hour ensemble forecasts of typhoon tracks of 31 typhoons over the Northwestern Pacific in 2013 were conducted using the weighted bias-removed ensemble mean method. Error analysis indicates that the results of ensemble forecasts using the fixed training method with a constant weighting factor are quite sensitive to the selection of training samples,showing significant fluctuation of error for different training samples,while the error of ensemble forecasts using the moving training method with a variable weighting factor shows a declining trend with the increase of the number of training samples and tends to be stable when the number reaches 40. Comparisons show that twin typhoons in the training period have a large influence on the forecast accuracy,and the accuracy is significantly increased by removal of the influence of twin typhoons. Based on comprehensive comparisons of forecast results of2013＇s typhoon tracks,the moving training method with 40 training samples and without consideration of twin typhoons in the training period is recommended.