Avalanche problems; an important part of the Norwegian forecast, and a useful tool for the users

Abstract

The Norwegian Avalanche Warning Service uses avalanche problems in their bulletins to provide a compact, yet exact, description for the end user of the current conditions. The Norwegian avalanche problems consist of the following elements: The type of expected avalanche, the cause of the avalanche, the likelihood, expected size, amount of extra load that is necessary for triggering and finally where in the snowpack we expect the avalanche to be released. Observers submitting observa- tions and forecasters have the opportunity to make different combinations of all the available ele- ments. Forecasters can choose up to three avalanche problems when composing the bulletin. A standard sentence and set of icons is automatically generated depending on the chosen elements. Given the large forecasting regions, few weather stations and field observations, our avalanche prob- lems are an attempt to make the avalanche bulletin more useful to the end user. Feedback on the use of avalanche problems show that they provide a useful and good starting point for pre- trip planning and that they are also useful for evaluation during the trip. Avalanche problems have also been useful for educational purposes, both at the website varsom.no and for people teaching avalanche courses.