A 2D version of a 3D nonhydrostasic meteorological model is used to simulate the effects of atmospheric front propagation over a valley. The front surface is described in the model by an equation for advection of a scalar substance, which is solved by a third-order semi-Lagrangian procedure. A leap-frog type scheme is used for time discretization. Special-purpose operators of space discretization are used to provide conservation of momentum and scalars. The results of 2D model simulations show reasonable behavior of cold front propagation over a valley as compared to the available measurement and simulation data.