摘要
本文通过对2005年5月12-15日暴雨天气过程多普勒雷达资料和常规天气资料的分析发现中低空水汽辐合、低层垂直风切变引起的辐合是产生强降水的重要原因。单体的合并也起了一定的作用。而且单体的合并与低空切变有关。通过多普勒雷达观测资料分析表明：这次暴雨的几次强降水都是强对流单体造成的，每个阶段回波演变都有回波生成、合并、减弱过程，雷达多普勒速度表明都存在风向辐合（NW和SW），具有涡旋特征。
Based on the characteristics of Doppler weather radar data and conventional meteorological data, the disatrous weather case occurred on May 12-15, 2005 is analyzed. The results show that the low-and middle-level convergence of moisture and convergence caused by low-level vertical wind shear are the important reasons of the torrential rain. Convective cell and the cell＇s mergence also play an important role. Moreover, the cell＇s mergence have a connection with the low-level shear. Evolution features of radar echo on each phase include developing, strengthening, merging and weakening. The analysis of the Doppler radar velocity field also indicates that there exits the convergence of northwest wind and southwest wind appeared to have vortices.
关键词
低层切变
暴雨
雷达回波
中尺度特征
Low-level shear Torrential rain Radar echo Mesoscale features
