山东一次区域性暴雨中尺度特征分析

摘要

利用常规资料、地面自动站资料、FY2C卫星云图TBB和多普勒天气雷达资料,对2009年5月9-10日发生在山东的春季区域性暴雨进行分析和研究.结果表明:①强降水是在低层冷空气和深厚西南暖湿气流交汇的过程中产生的,副高异常偏强,制约850～700 hPa切变线和地面辐合线停滞少动,产生较长时间的降水.②地面辐合线的形成和维持激发了边界层的辐合上升运动,为暴雨区提供了充足的水汽,冷空气从边界层楔入,与暖湿气流汇合并抬升暖湿气流辐合上升,使上升运动加强,降水增幅.③中尺度对流系统是造成暴雨的主要中尺度系统,多个单体更迭并移经同一区域,形成“列车效应”而产生区域性暴雨.④雷达径向速度图中逆风区和不同高度(超)低空急流的大小对短时强降水预报有一定的指示意义.%By use of conventional data, as well as AWS, FY-2C TBB and Doppler weather radar data, the causes of a rcgional rainstorm occurred in Shandong from 9 to 10 May 2009 are analyzed. The results indicate: (1) The severe precipitation was produced when the cold air met with the southwest warm wet air. The strongcr subtropical high made the surface convergence line and the shear line at 850 and 700 hPa stagnated; therefore, the severe precipitation is maintained persistently. ( 2 ) The formation and maintenance of the surface convergence lines stimulated ascending motion in the boundary layer and provided sufficient water vapor for the storm, and the cold air met with the warm wet air, leading to the convergence and updraft. As a result, the ascending movement strengthened and the precipitation increased. (3) The mesoscale convective system (MCS) was the major influencing system, and many multi-cell storms alternated and moved through the same region to form "train effect" and produce a regional rainstorm. (4) The low-level jets of different heights and the head wind zone in the radar radial velocity chart have indicative significance to severe precipitation forecasting.