The model forecast is from the WRF-ARW model at 9 km resolution. The topography is taken from the Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) at 0.00416 degrees resolution (about 400 m, or roughly a quarter of a mile). The snow limit is calculated from the temperature at several pressure levels and the corresponding geopotential height, this together with the high resolution topography produces a realistic snowfall map. We also take into account the increasing precipitation with altitude, using well tested parameterizations.