In this work we have examined the baroclinic instability in a linear two layer model, where the perturbations are presume to depend the latitude. From the linear equations we have computed the growthrates and speeds of propegation of the unstable disturbances. The results show that the meridional effect destabilize the zonal waves, and give a numerical increase in the propagation speeds. The reference is the geostrophic balanced model. Finally we study the same sizes when the dimension in the zonal and meridional plane are different. We find an increase in the growthrates when the meridional wave number grows.