Abstract:The comparative analysis of the severe convective weather processes on 29 July 2015 and 14 July 2018 is carried out based on conventional observation data, automatic weather station data, NCEP/NCAR GFS analysis data, Doppler radar data and satellite data. The results demonstrate that there was a cold vortex in easterlies at 200 hPa, an easterly wave at 500 hPa but subtropical high at 850 hPa in both cases, which means the weather events were under the influence of upper-tropospheric cold vortex in easterlies. The vortex in easterlies with shallow depth, high relative humility and low temperature was significantly different from typhoon or easterly wave. Furthermore, the cold vortex could not bring gale and rainstorm by itself. However, it inccurred severe convection with thunderstorm, heavy rain and hail triggered by surface mesoscale convergence line which was caused by east and west winds on 29 July 2015. On the contrary, there was no occurrence of convection due to the lack of trigger mechanism on 14 July 2018. The divergent rotation characteristics in front of the cold vortex moving could enhance the ascending motion so that it made the convection severely, which was significant different from the weather systems under westerlies. Therefore, it should be paid special attention to in the early-warning operation.