Starting from the 2004 winter season, the SNOWPACK snow cover model has been operational at the Avalanche Forecasting Centre in Arabbe (Dolomites, Italy). Snowpack characteristics, such as snow depth, temperatures, hardness, density, wetness but also snow microstructure, laying and stability, are modelled using date from automatic weather stations. Until now there has been no statistical validation of the SNOWPACK model for the Dolmites climate area. throughtout the 2009-2008 winter, snow pit observations were performed weekly in a study plot close to the automatic weather station in "Monti Alti di Ornella". Snow profiles were compared to simulation results in both a qualitative and a quantitative way.
Early in the season, agreement between measured and simulated snowpack characteristics is good (74%). The quality of the simulations decreases with the start of the melt season. Snow depth is generally well simulated, although the model tends to underestimate the snow depth early in the season and overestimate it late in the season.
Analyzing the effects of wind on the snow cover, the SNOWPACK model proves unable to simulate the densification of the surface layers under strong wind conditions (wind crusts). We introduce and describe an empirical "wind effect" function providing additional densification under strong winds. This results into improved simulations of snow density and other parameters, especially in the second half of the season.