Two Years Experience of Operational Avalanche Forecasting using the Nearest Neighbours Method

Abstract

An operational version of avalanche forecasting using the nearest neighbours method was given to the Parsenndienst, the safety service in the ski area of the Parsenn region. They have tested this NXD method through two winters and have now decided to acquire their own computer with a mass storage unit in order to run the programme. The forecasting is being run by the patrolmen themselves, including the input of weather and snow data, and they also update the file of avalanche and blasting activities with the details of operations, as required for ammunition accountancy. The nearest neighbours method provides the patrolmen with a list of the avalanches that have occurred on the 10 d in the past 20 years most similar to the day being considered. These data represent the nearest neighbours of the method's name. The men are able to interpret the list correctly without any need of instruction, and rely on getting information from it which will help them to decide when and where to use (or not to use) explosives. The method of interpretation of the information supplied is illustrated by way of four specific examples.