The Swiss snow-cover model SNOWPACK is presently used in many applications from snow sports and engineering to climate change assessment but also for avalanche warning. The core routines are packed in a library that also serves as the basic module for the land surface scheme Alpine3D. The separate application MeteoIO handles all input data in both applications. These components, including a visualization tool, are available as open source packages ( Since 2002, the year three papers describing the model in detail appeared (for example, see Lehning et al., 2002), SNOWPACK evolved in many respects. Based on newly acquired data sets, we updated the parameterizations of the density of new snow (see Schmucki et al., submitted) or of the albedo. We also revisited some concepts of the model such as snow settlement: we now divide the stress applied to the snow into a purely static overburden and a stress rate dependent term that allows mimicking the relaxation behavior of new and older snow. In addition, we adapted the temperature dependence of viscosity to cover a large temperature range from about -70 °C up to the melting point (Groot et al., 2013). Finally, we maximized the accuracy of both mass and energy balance. This is necessary for implementing advanced water transport equations such as the recent solver for the Richards equation (Wever et al., 2013).