Abstract: A severe local rainfall case occurred on September 15, 2016 in the coastal region of Zhejiang province is analyzed based on a synthetic dataset including conventional observations, radar data, and ERA-Interim reanalysis data with horizontal resolution of 0.5×0.5 degrees. Results show that the heavy rainfall was directly produced by the outside spiral rainbands from typhoon Meranti. On September 15, 2016 the sufficient moisture, vapor transportation and the unstable atmospheric stratification were evident in eastern coastal region. The combined effects of the boundary layer convergence line, topography and the front part of boundary layer jet induced the strong boundary convergence and updraft flow formed and triggered the convection. At upper level of troposphere(200 hPa), the overlap of the right back side of upper-level jet and divergence zone provided intense divergence, which is advantage to the development and maintenance of lower-level convergent updraft, ultimately led to occurrence of the heavy rainfall. Comparison of the intensities of boundary southeasterly jet and convergence line between the model forecasts and observations uncovered that the model forecasts is weaker than the observations, which probably is the primary factor that results in the underestimation of the heavy rainfall intensity in each global numerical weather prediction center. It shows that the boundary southeasterly jet and convergence line have played an important role in this heavy rainfall process.