Item: On Estimating Avalanche Danger From Simulated Snow Profiles
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Title: On Estimating Avalanche Danger From Simulated Snow Profiles
Proceedings: International Snow Science Workshop Grenoble – Chamonix Mont-Blanc - October 07-11, 2013
Authors:
- Sascha Bellaire [ Dept. of Civil Engineering, University of Calgary, AB, Canada ] [ Institute of Meteorology and Geophysics, University of Innsbruck, Tyrol, Austria ]
- Bruce Jamieson [ Dept. of Civil Engineering, University of Calgary, AB, Canada ]
Date: 2013-10-07
Abstract: Estimating avalanche danger is the primary goal of avalanche warning services. Typically avalanche danger is estimated based on a variety of information such as manual snow profiles, avalanche observations as well as weather data. However, this required information is often not available especially in data sparse areas, which are common in Canada. It has been shown that coupled snow cover and numerical weather prediction models can provide such information on the snow cover. For this study we simulated the snow cover for three elevation bands – alpine, tree-line, below tree-line – at Glacier National Park, B.C., Canada for the winter season 2012-2013 between December and March. Snow cover simulations were performed using the Swiss snow cover model SNOWPACK forced by weather data from the Canadian high-resolution numeric weather prediction model GEM-LAM. Experienced forecasters estimated the regional avalanche danger (Low to Extreme) daily during the same period for the three elevation bands. Multivariate classification trees were used to estimate the avalanche danger from the simulated profiles. Classification trees were built using four parameters derived from the simulated profiles. These four parameters were the new snow amounts – maximum over 24-hours and 3-days – as well as measures for the likelihood of triggering and the expected avalanche size – based on a skier stability index and the depth of a critical layer. A comparison of the avalanche danger estimated from the simulated profiles with the forecasted avalanche danger showed that the avalanche danger was estimated correctly with an accuracy of 77% for the alpine, 76% for tree-line and 70% below tree-line – overall accuracy about 74%. Although the simulated avalanche danger tends to be slightly underestimated, especially for the alpine and treeline, such a model chain can be a valuable tool for avalanche warning services especially for data sparse areas.
Object ID: ISSW13_paper_O1-01.pdf
Language of Article: English
Presenter(s): Unknown
Keywords: avalanche warning, avalanche forecasting, avalanche danger, SNOWPACK, snow cover simulations, numerical weather prediction, data sparse areas
Page Number(s): 154-161
Subjects: avalanche forecasting snowpack avalanche warning
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