【摘要】 2005年第9号台风麦莎在浙江台州登陆后北上,北京市气象台于8月6日发布预报,认为受台风影响北京将出现暴雨天气过程。实况是北京城区只出现了小到中雨,郊区为中到大雨,只有东北部地区出现了暴雨。为了加深对华北台风暴雨的认识,应用常规气象资料、卫星云图对这次预报不理想的原因进行了分析。总结出的原因主要是(1)关于台风路径的数值预报误差较大,预报路径比实况偏西200km以上。(2)台风麦莎的结构不对称,云系和强降雨主要分布在台风的东部和北部,而北京处于台风的西北部。(3)台风外围的东南急流只出现在120°E以东,强度较弱。(4)华北高压的存在阻挡了河套西部冷空气东移,因而不能形成中低纬度系统相互作用的形势。针对上述分析提出了预报着眼点和改进预报服务的建议。更多还原

【Abstract】 Typhoon Maisha(0509) moved northward after landing on Zhejiang. Beijing Meteorological Observatory predicted that the typhoon would bring heavy rainfall to Beijing. Actually, there was the heavy rain only in the northeastern Beijing and the moderate rain in the most of the city. To understand typhoon heavy rainfall in Huabei deeply, an analysis of this unsuccessful forecast is performed by using the conventional meteorological data and the satellite images. The results show that (1) the numerical forecast of the typhoon track had an error, (2) the typhoon maintained asymmetry structure and heavy rain occurred only in the east and north of the typhoon, (3) the weak southeast jet occurred mainly in the east of 120°E and (4) since Huabei high pressure obstructed cold air from the great band of Yellow River moving eastward, the interaction between low-latitude and middle-latitude synoptic system could not formed. In addition, it provides some instructions for the forecast and service of typhoon heavy rainfall in Beijing.更多还原