Item: ALL-WEATHER AVALANCHE MONITORING: RAPID RADAR DEPLOYMENT SUPPORTING DECISION MAKING IN JUNEAU
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Title: ALL-WEATHER AVALANCHE MONITORING: RAPID RADAR DEPLOYMENT SUPPORTING DECISION MAKING IN JUNEAU
Proceedings: Proceedings, International Snow Science Workshop, Whistler, BC, Canada, 2026
Authors:
- John Bressette [ City and Borough of Juneau, AK, USA ]
- Pat Dryer [ Alaska Department of Transportation & Infrastructure, AK, USA ]
- Michael Janes [ Alaska Electric Light & Power Co., AK, USA ]
- Severin Stähly [ Gravimon AG, Zurich, Switzerland ]
- Susanne Wahlen [ Gravimon AG, Zurich, Switzerland ]
Date: 2026-09-28
Abstract: The city center of Juneau, Alaska, lies between the sea and steep mountain terrain, with several neighborhoods located in avalanche runout zones. During the December 2025–January 2026 winter storm, record snowfall combined with sustained cold temperatures created extreme avalanche hazard conditions across coastal South Alaska. The City and Borough of Juneau issued evacuation advisories for exposed neighborhoods, while continued snow- and rainfall further increased the hazard. A State Disaster Declaration enabled rapid access to state and federal support. As part of the emergency response, a Doppler radar system for real-time avalanche detection was procured, delivered, and installed within 48 hours. Positioned across the fjord, the system monitors multiple avalanche paths at distances of up to 3 km. The radar operates continuously, independent of visibility conditions, providing reliable detection during storms, snowfall, darkness, and low cloud cover — periods when conventional observations are severely limited or not possible. The system automatically detects avalanche events and provides real-time alerts, including location and event metadata, via a user interface accessible to avalanche professionals and emergency managers. Each detection is synchronized with video from an integrated camera, allowing users to review events and validate radar signals when visibility permits. This combination of continuous detection and visual confirmation supports both immediate situational awareness and retrospective analysis. Operationally, the radar proved particularly valuable during periods of no visibility, enabling practitioners to track avalanche activity in real time and adjust hazard assessments accordingly. This improved confidence in decision-making related to evacuations, road safety, and public communication. The system also provided insight into avalanche frequency, timing, and spatial distribution across monitored paths.
Object ID: ISSW2026_P4.55.pdf
DOI: https://doi.org/10.15788/1790099403
Language of Article: English
Presenter(s): Severin Staehly
Keywords: avalanche radar, Doppler detection, urban avalanche hazard, evacuation decision-making, Juneau, Alaska
Page Number(s): 2438 - 2442
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