2016年西北太平洋台风活动特征和预报难点分析

摘要

The characteristics of typhoons in western North Pacific in 2016 are analyzed by using the besttrack data,the CMA operational forecast data and ECMWF NWP and EPS products.The results show that no typhoon formed in the first half year but many were seen in the midsummer and autumn.This phenomenon was related to the conversion from E1 Ni(n)o to La Ni(n)a of the eastern equatorial Pacific SST.In some cases,the TC track forecast errors for long lead-time are extremely large,which attributes to the large spread of EPS.To improve the TC track forecasting skill,the regularity of systematic bias of numerical models could be found.The TC intensity forecast error for 24 h is larger than 5 m · s-1,which is unusual for the past decade.For individual cases,the extreme errors are 20-26 m · s-1.Almost no improvement in the TC intensity forecast skill over the recent decades.The main reason is the lack of reliable objective intensity forecasting technique.The qualitative analysis of the intensity change is not enough in the operation.So,it is urgent to establish a quantitative and fine forecast method on TC intensity to improve the TC forecast skill.%利用历史台风最佳路径资料、2016年台风最佳路径实况和中央气象台台风路径强度实时预报资料,以及ECMWF数值预报和集合预报产品,对2016年西北太平洋台风活动的主要特征和预报难点进行了分析,结果表明:1-6月的淡季空台风和盛夏秋季多台风现象均与2016年赤道海温由厄尔尼诺向拉尼娜转换有关;长时效路径预报误差有时异常偏大,可能与集合预报产品的发散度很大有关,但是如果能够掌握数值天气预报对大尺度天气系统预报的系统性偏差,也可以做出精度更高的预报;24 h强度预报误差超过了5m· s-1,这种现象在过去十多年的业务预报中并不多见,个别最大误差竟达20～26 m· s-1.强度预报的大误差与强度预报中没有定量产品可供参考有关,定性地分析台风强度变化规律对于提高强度预报作用很小,所以急需建立和发展定量和精细化的强度预报方法.