ECMWF对不同天气形势下影响浙江台风的路径预报评估  

Evaluation on ECMWF typhoon track forecast that affects Zhejiang province under different synoptic situation

作　　者：杨亦萍 刘力源[1] 倪钟萍 高丽 YNAG Yi-ping;LIU Li-yuan;NI Zhong-ping;GAO Li(Taizhou Meteorological Bureau,Taizhou 318000 China;Luqiao Meteorological Bureau,Taizhou 318000 China)

机构地区：[1]台州市气象局,浙江台州318000 [2]台州市路桥区气象局,浙江台州318000

出　　处：《海洋预报》2019年第2期68-76,共9页Marine Forecasts

基　　金：浙江省预报员专项(2016YBY20)

摘　　要：对2012—2016年影响浙江台风进行天气形势场基本分型,依次是:(Ⅰ)东侧副高+浅槽型、(Ⅱ)副高+深槽\低涡型、(Ⅲ)带状副高型、(Ⅳ)副高西伸脊型、(Ⅴ)近海块状副高型、(Ⅵ)其他型。基于此对ECMWF台风路径预报进行评估,包括路径预报距离误差、移向误差和二者的分布特性。结果表明:(1)不同天气型的台风预报:24 h、48 h、72 h的平均距离误差为:57 km,105 km,183 km,其随时效增长增大,以Ⅰ类、Ⅱ类预报效果最差,Ⅲ类和Ⅳ类效果较好,与此对应路径多为登陆浙闽交界或者登陆浙江后西行和登陆台湾二次登陆闽中或登陆闽中转向北上;移向误差绝对值看:24 h、48 h、72 h绝对移向误差分别为5.41°,4.85°,6.46°,从移向偏差看,24 h预报移向总体偏右概率大,而对Ⅰ类预报偏左概率大,Ⅲ类、Ⅳ类预报偏右概率大;Ⅳ、Ⅴ型偏离程度小,Ⅱ型偏离程度大,Ⅰ型、Ⅳ型、Ⅴ型偏离程度随时效增长变化较小,较为稳定,Ⅱ型和Ⅲ型较不稳定;(2)从两种误差的分布可知:影响浙江的台风24 h距离误差主要在100 km内,移向误差范围是-10°～10°;随预报时效增长,离散程度增强,说明移向误差随着距离误差的增大而增大。Based on ECMWF typhoon data from 2012 to 2016, the synoptic situation that affects Zhejiang province could be categorized into six types:(I) Subtropical High + shallow upper trough,(II) Subtropical high + deep upper trough,(III) Banded subtropical high,(IV) Subtropical high western ridge,(V) Blocky subtropical high,(VI) Others. This article evaluates the ECMWF typhoon track prediction, including the distance error, moving direction error as well as their distribution characteristics. It is found that the average distance error of the forecast periods 24 h, 48 h, 72 h are 57 km, 105 km and 183 km, respective. The forecast accuracy is lowest for type I and II, while it is relatively higher for type III and IV, which mostly makes landfall at the junction of Zhejiang and Fujian provinces, in Zhejiang province and moves westward, and in central Fujian and moves northward. The moving direction error of the forecast periods 24 h, 48 h, 72 h are 5.41°, 4.85° and 6.46°, respectively. The probability of moving direction errors to the right is large in the 24h forecast. The moving direction error shows high probability in type I, type III and IV to the left and right, respectively. The degree of deviation is smaller in type IV and V, while it is larger in type II. Furthermore, the degree of deviation in type I, IV, and V change slightly along with the increase of forecast period, while type II, and III are more unstable. We further find that the distance error of forecast period 24 h is mainly within 100 km, and the moving direction error is between -10° and 10°. The degree of dispersion increases along with the increase of forecast period, indicating the moving direction error increases with the increase of distance error.

关 键 词：ECMWF 台风路径 距离误差 方向误差 预报评估 

分 类 号：P457.8[天文地球—大气科学及气象学]