2009年5月9—10日山东大暴雨天气分析

Analysis of the Heavy Rainfall Event during 9-10 May 2009 in Shandong Province

利用常规气象观测分析资料和卫星、雷达资料,采取天气学诊断方法,从大尺度环流背景、降水天气影响系统、物理量场、急流等方面,初步分析了山东省2009年5月9—10日大暴雨天气的成因。结果表明:此次大暴雨是在稳定大尺度环流背景下、低层中尺度切变线在华北南部稳定少动造成的;大暴雨落区位于低空急流的左前方、高空急流轴的右后方、低空切变线以南、地面冷锋以北的交汇区;从南海到山东省中北部的水汽通道为这次大暴雨提供了充足的水汽来源;地面冷锋是这次大暴雨不稳定能量释放的触发机制;中尺度对流复合体(MCC)的自西向东移动是产生区域性大暴雨的直接原因。

With the conventional meteorological observation data, satellite images and radar data, the heavy rainfall during 9- 10 May 2009 in Shandong Province is analyzed in view of the aspects of large-scale circulation, the dominating synoptic systems, multiple physical indexes and the jet. It is summarized that the heavy rainfall occurs in the environment of stable large-scale circulation with the stable low-level shear line in the south of North China. The rainfall is located on the left front side of the low-level jet line and the right back side of the high-level jet line, as well as the area between the south to the low-level shear line and the north to the surface cold-front. The water vapour channel from South China Sea to the north of Shandong provides an abundance of vapor for the rainfall. The surface cold front is the mechanism to release the instability energy. The moving of the mesoscale convective complex （MCC） from west to east causes the rainfall immediately.