Impact of the eastward propagating convection originated from the second-step terrain on the downstream severe convection systems during the summertime in East China

Severe convection weather east of the second-step terrain in East China often induces serious damage to social production and economy. This study focuses the features and mechanisms of the severe convection systems producing heavy rainfall impacted by the eastward propagating convection. Firstly, based on the observation data, the cases during the summer between 2000 and 2012 are divided into three main categories: eastward propagating convection continuing to develop; eastward propagating convection triggering new convection and eastward propagating convection strengthening local generated convection. Based on the synoptic circulation of the three categories, ideal and sensitive simulations are designed to diagnose quantitatively the trigger and development of severe convection systems impacted by the eastward propagating convection originated from the second step terrain as well as the effect of vertical wind shear and water vapor on the severe convection systems.