Haines Pass

Avalanche danger is rising rapidly with incoming snowfall and strong wind loading. New and wind-drifted snow over weak, sugary layers are producing unstable conditions, and natural avalanches are expected. Avoid avalanche paths and runout zones. Even small features on slopes steeper than 30 degrees—especially gullies and steep-to-flat transitions—can produce dangerous avalanches.

Snowpack & Avalanche Problems

An incoming series of low-pressure systems, following three weeks of Arctic outflow winds and record-setting low temperatures, is creating a unique and potentially dangerous snowpack structure. Weak, sugary faceted snow exists near the surface on slopes that were sheltered from northly outlfow winds and will become increasingly difficult to assess once buried beneath new storm snow, creating a smooth, low-friction bed surface.

As new snow accumulates—especially with rapid loading from heavy precipitation or wind—failures at the new/old snow interface are likely. These failures can propagate widely across terrain features, capable of producing large and destructive natural and human-triggered avalanches. While exact snowfall totals and rates remain unclear, avalanche conditions can change quickly as snowfall intensity, wind, or temperatures increase during the storm.

In areas where this weak, sugary faceted snow did not form due to wind scouring, bonding within the storm snow may be stronger; however, storm slab instabilities and wind-loaded slopes remain concerns, especially as winds vary in direction from north to south and increase in intensity. With multiple overlapping instability factors present, managing risk by changing aspect or elevation alone is unlikely to be effective when selecting terrain.

Travel Advice 

Given this snowpack structure and the approaching storm, avoiding avalanche terrain is the safest approach as precipitation increases. This includes slopes steeper than 30 degrees and connected terrain—meaning even flat areas below steep slopes overhead. Avalanches may run farther than expected, so stay out of runout zones such as gullies, valley bottoms, and other terrain where debris can accumulate. Even relatively small slopes can have serious consequences.

Avalanche hazard will increase rapidly with heavy snowfall, strong winds, and warming temperatures, with the most dangerous conditions during and immediately after the storm. Brief breaks in the weather can still coincide with peak instability despite improved visibility. Monitor local weather stations and the National Weather Service (NWS) forecast to track storm timing and severity.

Look for signs of instability, including recent natural avalanches, cracking, collapsing, and whumphing—clear indicators that weak layers are failing. Keep terrain choices simple and conservative, use cautious group management, and limit exposure by traveling one at a time in areas where avalanche terrain cannot be avoided.

While new snow ultimately contributes to longer-term snowpack development, patience is critical during periods of rapid loading and persistent instability. Deep snow can make lower-angle terrain more difficult to travel, increasing the temptation to seek steeper slopes. Continue gathering observations and hold off on higher-consequence terrain until conditions stabilize.

Patterns show that accidents often occur when instability is highest, both during storms and on clear days following a storm when persistent weak layers remain in the snowpack. 

https://utahavalanchecenter.org/avalanche-danger-scale 

Known Weak Layers

With limited observations over the past month, there is a high degree of uncertainty around how previously identified weak layers are responding to recent snow, wind, and prolonged cold temperatures. These layers may become more reactive as they are loaded by new snow and wind.

Layers of concern include:

• Near-surface facets (sugary snow) that formed between December 7th–26th
• A buried surface hoar layer reported in mid-November near Chilkat Pass
• A widespread melt-freeze crust that formed in early December up to approximately 2,500–3,000 feet

Additional Hazards

Near-zero temperatures, severe winds, and heavy precipitation add another layer of hazard. These conditions can slow rescue efforts, reduce mobility, and increase the severity of injuries if something goes wrong in the mountains.

Early Season Considerations

Conditions will continue to evolve, and the snowpack will vary across short distances as you move between aspects, elevations, and terrain features. Keep assessing the snow as you travel. We currently have very limited information and funding, so please read and submit observations and report any avalanches you see.  Consider supporting the center by donating or becoming a member or community partner.

It’s still early season. Practice companion rescue skills with your partners and make sure everyone’s beacon, shovel, and probe are functioning properly—and that each person knows how to use them. Use extra caution around shallow snowpack areas, rocks, cliffs, and buried vegetation that can increase the risk of injury in a fall or crash.

Regular general avalanche information products are published every Friday morning at 6am during the 2025-2026 winter season.