An Energy and Mass Model of Snow Cover Suitable for Operational Avalanche Forecasting

A numerical model has been developed to simulate energy and mass evolution of snow cover at a given location, as a function of meteorological conditions: precipitation, air temperature, humidity, wind velocity, and incoming short-wave and long-wave radiation. This model, named CROCUS, was first tested on a well-instrumented field during a whole winter, showing its ability to simulate the important phenomena affecting the evolution of the snow layers: high temperature gradients, wetting, compaction, and melting-freezing cycles. A second test was conducted at two locations in the French network used for operational avalanche forecasting. Though the weather observations are made there only twice daily, the snow profiles calculated by the model were very close to those obtained once a week by a pit observation. CROCUS proved itself sufficient to be considered now as a useful objective tool for operational avalanche forecasting.