A thunderstorm is a severe convective weather that can result in weather disaster.To analyze the possible reason for surface gusts associated with thunderstorms,a high resolution numerical simulation of a severe thunderstorm occurred in Beijing on 31 May 2014 was carried out.Based on the equations of momentum and mass weighted kinetic energy,the budget of meridional momentum and kinetic energy was investigated with the simulation output data.The fluxes transport of meridional momentum and mass kinetic energy was examined.It was shown that local changes of meridional momentum and mass kinetic energy near the surface were primarily dominated by the divergence of meridional momentum and mass kinetic energy fluxes.In the middle and lower troposphere,the rear inflow in the stratiform zone and the descending flow in the convective zone transported downwards meridional momentum and mass kinetic energy,which were converged with horizontal fluxes of meridional momentum and mass kinetic energy near the surface.The converged fluxes were then horizontally transported to the front of the convective zone.Blocked by topography to the northwest of Beijing,the combined fluxes converged in the front,and intensified the southerly wind gust on the ground.Similar to meridional momentum,local changes in mass kinetic energy near the surface were primarily dominated by the divergence of mass kinetic energy flux.The rear inflow in the middle troposphere brought mass kinetic energy downward to the ground layer,and merged with the horizontal flux of mass kinetic energy near the surface.Relatively speaking,the horizontal flux of the meridional momentum and the mass kinetic energy of the near ground layer are mainly related to strong low-level southeasterly jet and more important than the downward flux transport.