Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Fresh snow and strong winds will increase the avalanche danger this afternoon. Choose terrain sheltered from the wind for safer and better quality riding.  Move off of steep slopes if you find blowing snow, wind-textured surfaces, or cracking around your feet or machine. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Natural and human-triggered avalanches have occurred on wind-loaded slopes during the last 24 hours.  Fresh snow and moderate to strong southwesterly winds will continue to build sensitive slabs downwind from ridges, saddles, and other prominent terrain features. Keep in mind:

    • Blowing snow points in the direction of fresh slab formation.
    • Signs of wind-affected snow include rippled surfaces, dune-shaped features, and cracking around your feet or machine.
    • Slabs formed by previous extreme winds can be found in unusual locations and may be stiff enough to support your weight.  They may show few signs of instability before releasing and can break well above you, propagating widely.

    Consider moving to less steep or more sheltered terrain if you encounter any of the above.  Slabs greater than 8 inches will be difficult to manage. Recognize that slab thickness can vary greatly across any given slope. 

     

    (12/19/2025)

    Etched surface snow and dune-shaped features (shown here) are obvious signs of wind-loading. Blowing snow is another clear sign that wind slabs are forming on the slopes below. Choose slopes that are sheltered from the wind for safer and better-quality riding. 

    Photo: Michael Reavis

Avalanche Discussion

A pair of avalanches reported Friday should catch your attention: A small human-triggered slab avalanche near Whitefish Mountain Resort and a large (D2) natural slab avalanche on Mount Penrose in the Flathead Range. Both occurred on wind-affected slopes. 

Today, I would anticipate a couple flavors of wind slab. You might find old drifts from yesterday’s strong to extreme winds. These likely range from soft to hard and may be found in unusual locations, including well downslope. Old hard slabs of wind-packed snow can surprise you since they might feel solid at first and even support the weight of a snow machine before breaking loose. Take a minute to assess what is under your feet if you find yourself riding on top of (instead of through) the snow's surface. Move to less steep terrain if you find a stiff slab resting on weaker, unconsolidated snow or poorly bonded to a crust below. 

Fresh (and possibly softer) slabs will form during today’s snowfall. These will form downwind from ridges, saddles, and other terrain features and will be evident from cracking around your feet or machine. Recall that even small avalanches can have serious consequences if you get knocked off your feet in extreme terrain (like this) or if you are carried into a terrain trap.

Uncertainty is growing due to our limited time in the field during the last few days. Most field teams decided to cancel their work plans due to damaging winds and treefall hazards. On that note, expect some access shenanigans if you are heading into the mountains today.  Look out for hazard trees and bring a saw and some friends to dispatch any blowdown you might encounter. Have a backup plan in case you get stymied, or give yourself some grace if you determine it's not worth the fight. Better days are hopefully on the way. 

Regions covered