Based on rainfall data from Tropical Rainfall Measuring Mission (TRMM) satellite,and data such as potential height,wind speed,and vertical speed from the Modern Era Retrospective-analysis for Research and Applications version 2 (MERRA-2) satellite,the moving path of typhoon 1909 (Lekima) and its rainstorm in Zhejiang,Jiangsu and Shandong provinces are analyzed.It is found that Lekima is a northward typhoon,and its moving path is mainly affected by the subtropical anticyclone and typhoon 1910 (Krosa).During its moving north,the typhoon inverted trough and the cold air in westerly trough cooperated and caused a large amount of unstable energy,which result in heavy precipitation.In addition,the low-altitude jet stream and the westerly trough provide favorable dynamic rising conditions for precipitation.The southwest monsoon and typhoon Krosa,as sources of water vapor and energy for typhoon Lekima,provide abundant water vapor for the rainstorm.