Item: AVALANCHE FORECASTING ON THE VERGE: EPHEMERAL SNOWPACKS, CLIMATIC SHIFTS, AND THE EVOLUTION OF ARIZONA'S WINTERS
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Title: AVALANCHE FORECASTING ON THE VERGE: EPHEMERAL SNOWPACKS, CLIMATIC SHIFTS, AND THE EVOLUTION OF ARIZONA'S WINTERS
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- W. Tanner Porter [ Kachina Peaks Avalanche Center, Flagstaff, Arizona, USA ]
- Paul Dawson [ Kachina Peaks Avalanche Center, Flagstaff, Arizona, USA ]
- Mathieu Brown [ Kachina Peaks Avalanche Center, Flagstaff, Arizona, USA ]
- Troy Marino [ Kachina Peaks Avalanche Center, Flagstaff, Arizona, USA ]
- Len Necefer [ Sonoran Avalanche Center, Tucson, Arizona, USA ]
- David Lovejoy [ Kachina Peaks Avalanche Center, Flagstaff, Arizona, USA ]
Date: 2026-09-28
Abstract: Arizona seems an improbable ski locale given North America's mountainous geography, yet its high-elevation sky islands support multiple winter backcountry zones and several ski areas, served by two of the lowest-latitude avalanche centers in the country. The Kachina Peaks Avalanche Center (Arizona's only nonprofit avalanche center) serves a local user base accustomed to low-tide, variable, and ephemeral snowpacks relative to other western ranges, and the Sonoran Avalanche Center (the first for-profit avalanche center in operation) humorously raises user-group awareness of climate change and non-snow avalanche activity. The 2025–2026 season, characterized by near-average precipitation punctuated by extreme warm periods and mid-season rain events even at the highest elevations, raises a question with implications well beyond Arizona: was this an anomaly or a preview? We examine historic patterns of winter snowfall, precipitation, temperature, and inter-storm intervals across Northern Arizona's forecast area to characterize the trajectory of ephemeral snowpack conditions in the Southwest. Our findings suggest that while a fully non-snow avalanche-forecasting future is not on the near-term horizon, the frequency of highly irregular snowpacks and extreme weather events that drive avalanche activity is rising. We emphasize that while the mechanics remain the same, the type, frequency, and distribution of historical patterns may be turning a new page. This finding supports the continued need for snow avalanche forecasting and outreach, while also pointing to the need for longer-term adjustments in operations and messaging. Equally important, ephemeral and feast-or-famine snowpacks present a distinct risk communication challenge. Established literature on hazard perception suggests that infrequent, high-variance, and seasonally unstable hazards are systematically underweighted by the public, and that forecaster credibility is harder to build and sustain when "normal" conditions are themselves in flux. Thus, avalanche centers operating on the climatic margins are functioning as early case studies for the broader community when communicating risk under non-stationary winters — including how to frame uncertainty, sustain user engagement across lean seasons, and prepare the public for an eventual expansion into forecasts that include related recreational hazards (obstacles, access challenges, rain-on-snow events, or even debris flows) without eroding public attention to the core snow forecast.
Object ID: ISSW2026_P2.49.pdf
DOI: https://doi.org/10.15788/1790099025
Language of Article: English
Presenter(s): Mathieu Brown
Keywords: Avalanche forecasting, climate change, risk communication, machine learning, snow-pack variability
Page Number(s): 1844 - 1850
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