Item: How Accurate are Weather Models in Assisting Avalanche Forecasters?
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Title: How Accurate are Weather Models in Assisting Avalanche Forecasters?
Proceedings: International Snow Science Workshop 2014 Proceedings, Banff, Canada
Authors:
- M. Schirmer [ Department of Civil Engineering, University of Calgary, Calgary, AB, Canada ]
- B. Jamieson [ Department of Civil Engineering, University of Calgary, Calgary, AB, Canada ]
Date: 2014-09-29
Abstract: Avalanche forecasters and decision makers strongly rely on Numerical Weather Prediction (NWP) models, for example on the forecasted precipitation amount. NWP models are rarely verified for mountainous regions during the winter season, mainly because of large observation errors. We validated two NWP models (GEM-LAM and GEM15) at 95 stations in the Western Canadian and Northwestern US Mountains. We used ultrasonic snow depth sensors to observe 24 hours new precipitation amounts. For the first time, a detailed objective validation scheme was performed highlighting many aspects of forecast quality. Overall, the models underestimated precipitation amounts, although low precipitation categories were overestimated. The finer resolution model GEM-LAM performed better in all analyzed aspects of quality. An analysis of the economic value of the studied precipitation forecasts showed that only mitiga-tion measures with low cost/loss ratios (i.e. measures which can be often performed) will benefit from these NWP models. This means that measures with large associated costs (relative to anticipated losses when the measure is not performed) should not or not primarily depend on forecasted precipitation
Object ID: ISSW14_paper_O3.04.pdf
Language of Article: English
Presenter(s):
Keywords: Numerical weather prediction models, validation, precipitation
Page Number(s): 75-79
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