Analysis of environmental characteristics affecting the evolution pattern of the frontal short-time heavy rainfall system

Using sounding and hourly data at ground automatic weather stations, the environmental field characteristics of four frontal short-time heavy rainfall events with different evolution patterns occurred in the prevailing period of Meiyu front in eastern China from 2010 to 2011 are analyzed. The results show that the evolution pattern and moving direction of MCSs are closely related to the distribution and motion of the dense isoline region of ground pseudo-equivalent temperature, and the formation of convective cells is relative to the ground convergence region. The dense isoline region of pseudo-equivalent potential temperature in the zonal, meridional and turning pattern of MCSs is in zonal, meridional and turning (from zonal to meridional) distribution, respectively. Moreover, the high value area of ground pseudo-equivalent temperature has a close relationship with the duration of heavy rainfall in different evolution patterns of MCSs.