How is avalanche danger described in public avalanche forecasts? We analyzed 6000 textual descriptions of avalanche danger in Switzerland, taking the perspective of the forecaster. Avalanche danger was described rather consistently, although the results highlight the difficulty of communicating conditions that are neither rare nor frequent, neither small nor large. The study may help to refine the ways in which avalanche danger could and should be communicated to the public.
In 1993, the European Avalanche Warning Services agreed upon a common danger scale to describe the regional avalanche hazard: the European Avalanche Danger Scale. Using published avalanche forecasts, we explored whether forecasters use the scale consistently. We noted differences in the use of the danger levels, some of which could be linked to the size of the regions a regional danger level is issued for. We recommend further harmonizing the avalanche forecast products in the Alps.
Avalanche hazard assessment requires a very precise estimation of the potential starting zone, which nowadays still depends, to a large extent, on expert judgement of avalanches. Therefore, a new algorithm for automated identification of potential avalanche release areas was developed. Potential avalanche release areas can be defined for varying snow accumulation scenarios, improving the automated estimation of release areas, in particular for frequent avalanches.