Advantage Forecasting Models

AVALANCHE FORECASTING MODELS Forecasting models can be more than visualization and data management tools. Indeed tools can help analyze complex data patterns. Analytical methods include deterministic, statistical, and/or expert systems, which are well known and researched. Some of these models are used in forecasting services others are presently at research stage.

DETERMINISTIC MODELS

Deterministic models try to simulate the snowcover with physical formulas. In hydrological sciences, numerical snowpack models are used for calculating the run-off in spring, but for avalanche forecasting purposes it is not enough to know the water equivalent of the snowpack. It is crucial to model the layered characteristics of the snowpack, including weak

They are located west of the Rocky Mountains and east of the Coast Mountains. Three main snow climate zones are generally distinguished: maritime, transitional and continental (LaChapelle, 1966; Armstrong and Armstrong, 1987, McClung and Schaerer, 1993; Mock and Kay, 1992). More recently Hägeli and McClung (2003) analyzed the avalanche characteristics in the Columbia Mountains in relation to the local snow climate and they defined the Columbia Mountains as having a transitional snow climate with a strong maritime influence. LaChapelle (1966) mentioned this type of snow climate as

Avalanche occurrence is not directly attributed to a specific major meteorological event, such as the 1-percent-annual-chance or 100-year snowfall. It is more commonly a result of a combination of weather and snow pack conditions. Unfortunately, the short period of recorded and observed avalanches and associated conditions that contribute to the risk make it difficult to develop return periods for avalanche-prone areas in Idaho. However, like other similar natural processes, a return period and probability of future occurrence can be developed from the available historical records. Avalanche risk assessment must provide for a conservative estimate of loss in consideration of accurate data and evidence, for example weather and snowpack observations, as well as make predictions for uncertainty. However, the traditional view of risk characterized by probabilities and consequences does not capture the subjective and contextual factors inherent in risk assessment. In reality, making judgments regarding the probabilities and consequences of avalanche occurrences under this inherent uncertainty is guided by social, ethical, legal and economic criteria (Aven & Korte, 2003; Flynn & MacGregor, 2003; Slovic, 2001). While the search for accurate and objective probability values is a goal of the risk assessment process, the process is driven by the boundary