2008年西北太平洋热带气旋定位和预报精度评定

Verification of the Tropical Cyclone Positioning and Forecasts over the Western North Pacific in 2008

依据《台风业务和服务规定》分析2008年TC业务定位和业务预报精度,结果表明:各方法的平均定位误差均小于24 km,平均为19.5 km;中央台的定位误差最小,为13.2 km;国内综合预报方法的24 h、48 h和72 h路径预报的平均距离误差分别为110.8 km、177.3 km和313.5 km;参与评定的各客观方法和数值方法的24 h、48 h路径预报在2008年度相对于气候持续法,均表现出正技巧,且连续两年都为正预报技巧;各方法24 h对登陆点的预报误差从几km到几百km不等,中央台对所有的登陆点均进行了预报,大部分均能提前20 h预报出登陆点信息。24 h和48 h近中心最大风速预报的平均误差分别为4.82 m/s和7.00 m/s,和历年水平相当。广西遗传神经方法的表现稳定,该方法对南海台风的强度预报具有良好的预报能力,24 h和48 h预报在各类方法中评分最高。

Positioning and forecast error analyses of tropical cyclones over the western North Pacific in 2008 show that:(1) average errors of tropical cyclone positioning are less than 24 km with an average of 19.5 km,and the error of National Meteorological Center(NMC) positioning is the lowest value of 13.2 km;(2) the average errors of subjective track forecasts in China are 110.8 km,177.3 km and 313.5 km for 24 h,48 h,and 72 h forecasts respectively;(3) all the objective forecasts and numerical weather forecasts perform better than the climate persistence method,with positive forecast skills in the two years;the 24 h forecast errors of landfalling position are from several kilometers to hundreds kilometers;the NMC gave all forecasts of typhoon landfalling position,and most of the forecasts could give information of the typhoon landfalling location before 20 h of landfalling;(4) errors of intensity forecasts are similar to past years with an average of 4.82m/s and 7.00 m/s for 24 h and 48 h forecasts, respectively;Guangxi statistical method performs well,which could have good performance for the typhoons in the South China Sea,and have the highest skills in all 24 h and 48 h forecasts of all forecast methods.