台风纳沙和海棠的预报着眼点分析  

Analysis of Forecast Focuses of Binary Typhoons Nesat and Haitang

作　　者：董林[1] 许映龙[1] 吕心艳 高拴柱[1] DONG Lin;XU Yinglong;LYU Xinyan;GAO Shuanzhu(National Meteorological Centre,Beijing 100081)

机构地区：[1]国家气象中心

出　　处：《气象》2020年第1期29-36,共8页Meteorological Monthly

基　　金：国家重点研发计划(2017YFC1501604);国家自然科学基金面上项目(41775048);中国气象局预报员专项(CMAYBY2018-090)共同资助

摘　　要：2017年7月的两个台风(1709号台风纳沙和1710号台风海棠)在近海发生罕见的近距离相互作用和环流合并,给登陆点的预报及二次登陆时的强度预报造成很大困难,包括ECMWF和NCEP等在内的大部分数值模式均未能较好地做出预报,但实际业务中的官方预报则较为准确。本文总结了实际业务中的预报经验,并对预报着眼点进行了分析归纳,主要包括:利用天气学模型、模式的偏差订正经验和集合预报结果等,分析模式对副热带高压等大尺度环流背景预报的合理性;通过分析双台风最靠近时刻的相对强度来确定主环流,从而判断两个台风的登陆时间差、各自的极值强度和陆上维持机制的差异;充分考虑登陆台湾的路径角度和过岛时间这两个影响因子,从而修订台风二次登陆时的强度。The accurate predictions of the first-time landing position and the second-time landing strength are very difficult because of the rarely-seen close distance for the binary typhoons Nesat(No.1709)and Haitang(No.1710).Although CMA issued an accurate official forecast,the performance of most models including ECMWF and NCEP was far from satisfactory.In this paper,forecast experience and focus in the forecasting operation are analyzed and summarized.The rationality of model prediction for the large-scale circulation such as subtropical high is analyzed based on synoptic models,deviation revision experience and the performance of ensemble forecasting system.The main circulation is determined by analyzing the relative strength of the closest time of the binary typhoons,so as to judge the difference between the landing time of the two typhoons,their extreme strengths and onshore maintenance mechanisms.Paying close attention to two influencing factors of the typhoon track angle with Taiwan’s central mountain range and cross-island time is helpful to revise the typhoon strength of the second-time landing.

关 键 词：双台风 二次登陆 环流合并 预报着眼点 

分 类 号：P456[天文地球—大气科学及气象学] P458