Snow forces are understood as forces originating from a very slow motion of the seasonal snow cover and acting on boundaries confining it. They depend on the total water-equivalent (a statistical magnitude with a certain probability of occurrence) and on mechanical characteristics of snow. The approximation of considering of snow as a Newtonian liquid fits the requirements for applications best. In this the only mechanical characteristics to be taken into account, besides density, are shear viscosity and Poisson’s ratio. They depend strongly on the snow structure. Generalizations are shown in which the snow cover is subdivided into layers having constant (Newtonian) properties. Non-Newtonian behaviour is also mentioned.