Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Sunny skies and warm temperatures will create dangerous avalanche conditions. Large wet snow avalanches will occur on slopes getting hit by the sun. Choose a route that avoids steep terrain during the heat of the day.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    The warm sun will wet the snow surface and cause it to slide. Avalanches may fail as wet loose or wet slab avalanches on sunny slopes. The travel advice is straightforward:

    • Plan a route that does not cross through steep solar aspects.
    • Shaded slopes will offer safer and better riding conditions.

    Today will be a good day to avoid steep solar aspects altogether.

    Cornice Fall: Intense solar input and heat may cause a few cornice failures today. Cornice failures are dangerous on their own, but may also trigger slab avalanches below, causing a more destructive avalanche event. Move quickly or avoid traveling beneath corniced ridgelines and give them a wide berth while on ridgelines.

    (4/25/2025) This image is taken from last season. Wet Loose avalanches on a west/southwest facing slope. Rocky outcroppings are often locations where you first see wet loose avalanches. Photo: Jackson George

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–3

    The threat of triggering a slab avalanche 1 to 3 feet deep may increase today with heat and sunshine. A wet loose avalanche or cornice fall may also trigger a large natural slab avalanche. Slabs that fail on solar aspects, which is the focal point of recent avalanche activity, will entrain wet snow and be especially dangerous.

    The safest option for managing this problem is by choosing lower-angled terrain. Although the weak layer exists on shaded aspects, recent avalanche activity suggests slopes that face southwest-south-east are more dangerous. IF you choose to ride in steep terrain, hedge your bets on planar slopes with smooth runouts. Avoid riding in consequential terrain that funnels into rocks, trees, or cliffs. Only expose one rider to steep terrain at a time.

    (1/10/2026)

    This image is taken after a snowmobiler triggered a large avalanche in the northern Whitefish Range. This avalanche failed on a southeast facing slope at roughly 6400 feet. The rider was caught, carried, partially buried.

Avalanche Discussion

Today’s warm, sunny weather is causing higher-than-usual uncertainty. At the most basic level, I am confident we will see avalanche activity. The challenging part of today is pinning down what kind of avalanches we will see and how big they will be, which will really drive the danger rating.

Simply put, expect spring avalanche problems. Cornice falls, wet loose avalanches, and possibly wet slab avalanches all may occur as the day progresses. My guess is that most will range from small (D1) to large (D2), but I won’t be surprised to see avalanches up to size 3 IF we see a wet slab avalanche cycle.

The upper snowpack has already begun to experience liquid water with warm temperatures. Guy found rollerballs on shaded aspects into the upper elevation band yesterday, and also observed perculation columns (liquid water) in the upper snowpack. As of yesterday, this water has yet to reach the weak layer responsible for all the avalanche activity last week. No refreeze occurred last night at middle elevations, allowing a steady flow of liquid water through the night. If water reaches the facet/crust today, which I think it will on south aspects, we may start to see larger, more destructive avalanches.

Howling winds have transported snow into slabs throughout the last week. Riders are finding small pockets of wind-drifted snow on leeward-facing terrain. Ride around areas where you see dune-shaped drifts or textured surfaces. These will be more common on upper elevation slopes that face north and east.

Regions covered