Snow avalanches are a major natural hazard with substantial impacts on society, including human safety and commerce. On the other hand, they also serve as an important ecological disturbance by modifying habitat for flora and fauna. Wet snow avalanches, including wet slab and glide avalanches, pose substantial risks to human life and infrastructure in mountainous areas throughout the world and can be particularly difficult to predict because they are relatively poorly understood compared to dry snow avalanches. Wet snow avalanches are caused by a weakening in snowpack layer strength, often triggered by rain, abundant sunshine, or warm temperatures. As temperatures increase and mid-winter rain events become more common due to a changing climate, wet snow avalanche frequency is expected to increase, and the timing of this avalanche hazard type will change. By analyzing the behavior of wet snow avalanches and the specific weather and climate factors that contribute to them, USGS scientists at the Northern Rocky Mountain Science Center (NOROCK) advance understanding of wet snow avalanches to better inform avalanche forecasting efforts, hazard mitigation, and land-use planning in avalanche terrain. 

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Here is an image of wet snow avalanche debris along the Going-to-the-Sun Road in Glacier National Park, MT. National Park Service (NPS) personnel in this image are accessing equipment on the other side of the avalanche debris. The USGS and the NPS at Glacier National Park have collaborated for 23 years on the Going-to-the-Sun Road Avalanche Program. The NPS closes a 56 km (34.8 mile) section of the road each winter due to inclement weather, heavy snowfall, and avalanche hazards. The annual spring opening of the road is a highly anticipated event for visitors and the regional economy is strongly tied to the road’s accessibility. Efforts to open the road each spring rely on a USGS-NPS partnership, which is based on the expertise of USGS avalanche scientists who provide on-site forecasting for the NPS’s road plowing efforts. The applied research from ongoing USGS avalanche studies supports forecasting efforts that guide the safety of this hazardous plowing operation.

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In collaboration with the USGS National Uncrewed Systems Office, NOROCK scientists use Uninhabited Aerial Systems (UAS) to map avalanches and calculate specific avalanche dimensions. To the right is a still image of a point cloud produced from a UAS equipped with lidar sensors that shows avalanche debris across the Going-to-the-Sun Road in Glacier National Park.

The USGS’s avalanche research at NOROCK is critical for understanding and mitigating risks to public safety and infrastructure posed by increasing wet snow avalanche frequency in a changing climate. Users of USGS avalanche research include the National Park Service, U.S. Forest Service, the Colorado Avalanche Information Center and Colorado Department of Transportation, the National Weather Service, and Burlington-Northern Santa Fe Avalanche Safety Department. These entities use our data for weather and avalanche forecasting as well as infrastructure planning efforts.

This research is supported by the Ecosystems Mission Area Land Change Science Program, the Alaska Climate Adaptation Science Center, the North Central Climate Adaptation Science Center, and the National Park Service.