关键词: 局地对流, 地形触发, 地面能量

Abstract:

By using conventional observation data and high density regional observation stations data, radar echoes and simulation results from the WRF model, an analysis about a local strong convective weather caused by weak cold air in mountainous area of the middle Shandong was done. The results show that the weather process occurred under the condition of unstable atmospheric state and the trough on 500 hPa was weak, and the influence of terrain in mountainous area couldn’t be ignored on triggering and strengthening the strong convection. The local convection was triggered easily at the northwest boundary of mountainous area, the middle scale low pressure center and maximum temperature gradient area. The simulation results of the WRF model show that the convergence caused by the flow around the terrain was favorable for convection strengthening, and the vertical circulation excited by windward slope was the main reason of the convection development. Under the weak environment field, when the convection was triggered, the strong radar echo would develop and strengthen along the high-energy zone of the ground.

Key words:  local convection, terrain triggering, underlying surface energy