2018年8月两次登陆北上台风移向的先兆信号分析

在分析台风“摩羯”（201814）和“温比亚”（201818）登陆北上异常路径的基础上，从近地面层气象要素场与台风位置动态配置入手，探寻了台风登陆后移向的近地面先兆信号，以此可修正数值模式的预报结果。主要结论如下:登陆后的台风尽管路径多变，但是近地面层气象要素还是会提供一些移向征兆。比如，地面3 h变压低值中心和地面露点高值中心，1 000 hPa高频流涡旋、渐近线或汇合点将是台风未来移动的方向；台风还有沿着流线密集带向其倒槽顶端移动的趋势。登陆后的台风没有趋暖性，而是沿地面温度低值区移动。由于地面要素受下垫面影响较为严重，所以在实际业务应用中应以地面3 h变压、地面露点与高频流场为主，地面温度和地面流场为辅。

Analysis of the Precursor Signals of Typhoon Moving North on Two Landings in August 2018

Based on the analysis of the northward anomalous landing paths of typhoons Capricorn (201814) and Winbia (201818), the near-surface precursor signals of typhoons after landing are explored from the dynamic configuration of near-surface meteorological elements field and typhoon location, so that the prediction results of the numerical model can be corrected. The main conclusions are as follows: despite the changeable track of the landing typhoon, the meteorological elements in the near surface layer will still provide some moving signs. For example, the 3-hour low-pressure center and the high-value center of the surface dew point, the 1 000 hPa high-frequency current vortex, asymptote or convergence point will be the direction of typhoon movement in the future;typhoon also has the trend of moving along the streamline dense belt to the top of its inverted trough. After landing, the typhoon has no warming tendency, but moves along the low value area of ground temperature. Because the ground elements are seriously affected by the underlying surface, the ground 3-hour pressure variation, ground dew point and high frequency flow field should be the main factors in practical application, and the ground temperature and ground flow field should be supplemented.