Item: BEYOND THE DANGER SCALE: A MULTI-SOURCE, INTERNATIONAL ANALYSIS OF AVALANCHE PROBLEM TYPES IN FATAL INCIDENTS (2017–2026)
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Title: BEYOND THE DANGER SCALE: A MULTI-SOURCE, INTERNATIONAL ANALYSIS OF AVALANCHE PROBLEM TYPES IN FATAL INCIDENTS (2017–2026)
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- Keith Gale [ Pinecrest Nordic Ski Patrol, Pinecrest, CA, USA ]
Date: 2026-09-28
Abstract: Avalanche danger ratings have appropriately received substantial research attention because they provide the primary regional summary of avalanche hazard. In contrast, avalanche problem types—now a central component of operational forecasting under the Conceptual Model of Avalanche Hazard—have received comparatively little quantitative evaluation despite conveying complementary information about the nature, location, and expected behavior of avalanche hazards. This study addresses that gap. It analyzes 883 fatal avalanche incidents (1,239 fatalities) from the 2017–18 through 2025–26 seasons using the International Fatal Avalanche Database (IFAD), a multi-source international fatal avalanche database drawing records from the United States, Avalanche Canada, seventeen EAWS member nations, Japan, and South America. To the authors' knowledge, this constitutes the most comprehensive multi-national problem-type fatality analysis yet published. Of 675 classified incidents (877 classified fatalities), the most operationally significant finding is that Persistent Slab (262 deaths; 29.9% of classified fatalities) generates its highest fatality counts at Danger Level 1–Low (38 deaths)—the highest count of any problem type at that level—and 47 at Level 2–Moderate, showing that low-to-moderate ratings do not necessarily mean persistent weak-layer hazard has resolved. Wind Slab accounts for the largest overall share (338 deaths; 38.5%), including 102 deaths at Danger Level 2–Moderate, confirming that regional danger ratings understate problem-specific risk at lower levels. Backcountry skiing and snowboarding accounts for the majority of activity-classified fatalities. Cross-agency classification differences at the Wind Slab/Storm Slab boundary are documented and addressed in the analysis. These findings suggest that Persistent Slab bulletin entries warrant explicit prominence at Low and Moderate danger levels independent of the overall rating, and that cross-agency problem-type harmonization is a prerequisite for further international safety analysis.
Object ID: ISSW2026_P4.42.pdf
DOI: https://doi.org/10.15788/1790099361
Language of Article: English
Presenter(s): Keith Gale
Keywords: avalanche problem types, danger scale, persistent slab, fatality analysis, international harmonization
Page Number(s): 1886 - 1893
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