Mesoscale analysis of an extremely heavy rain event in Jiangsu due to the effect of coastal northward-moving typhoon

Based on routine upper-air and surface observations, observations from intensive automatic weather stations over Jiangsu, Doppler weather radar and wind profile radar data, FY-2F satellite cloud images, and NCEP/NCAR reanalysis with 1°×1° resolution, we have conducted a mesoscale analysis of an extremely heavy rain event occurred in Jiangsu from August 7 to 8 in 2014.The results indicate that (1) this event, in which two severe precipitation areas with the greatest rainfall intensity of 109.2 mm·h^-1 located in the Daqiao town of Dafeng City and the Xingfu town of Nantong City, respectively, occurred under the influence of a coastal northward-moving typhoon (1411) Halong, the establishing of a ridge at Lake Baikal and the eastward moving and southward jumping of the Northeast China trough.(2) The short-period severe precipitation at Daqiao town was attributed to slowly-moving convective storms triggered by surface cold front and convergence line, and coordinated with low-level wind.(3) The short-period severe precipitation at Xingfu town was caused by several convective storm cells.Surface mesoscale vortex, which moved eastward along the Yangtze River in Nantong, then became stable and stationary due to the effect of advantageous topography and environmental vertical wind shear, triggered these cells.(4) The initial generation of convective cloud clusters has an indicative significance to the nowcasting of severe precipitation.