Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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

Today's sunshine will initiate a wet loose avalanche cycle in this week's bountiful snowfall. Rollerballs and mushy, unsupportable snow are signs you have worn out your welcome and need to move to a different slope. Slabs of wind-drifted snow can be found in unusual locations. Cracking in the surface snow directs you to seek softer snow in sheltered terrain.

If upper elevations do not warm as much as anticipated, the danger may only reach MODERATE on these slopes.

Avalanche problems

  • Loose Wet

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

    Today’s mostly clear skies will allow the strong April sun to melt the surface snow. Cold morning temperatures may delay the onset of this process on easterly slopes, but prolonged sun will eventually warm and wet the surface on many aspects.  

    Snow peeling off rock faces or dropping from tree branches could initiate rollerballs, a precursor to a wet loose avalanche. Slides will initially involve the Thursday/Friday snowfall, but could entrain the entire 1-2 feet of snow that rests above the stout crust formed in late March. The debris from these larger avalanches can travel a considerable distance on the underlying slick surface and, in larger terrain, reach the lower elevations. 

    Plan your day to stay ahead of the sun, including your afternoon exit. If you encounter a mushy snow surface, move to a shadier slope or lower-angle terrain without overhead hazards.

     

    (3/24/2022)

    This weekend's warming temperatures and sunny skies will develop a wet loose avalanche cycle. Slides will involve this week's plentiful snowfall and could reach D2 in size, which is large enough to bury, injure, or kill a person.

    Photo: Mark Dundas

  • Wind Slabs

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

    On Thursday, north and east winds blew at speeds capable of transporting recent snowfall. Expect to find fresh slabs in unusual locations, including on normally windward slopes. These features will increase in size and become more widespread as you gain elevation. They formed on various surfaces, including crusts and weak snow, which may contribute to their instability.

    Wind-stiffened snow can be identified by an etched surface and pillow or dune-shaped features.  

    Cracking under your feet or machine indicates you have found a sensitive slab. A stiffer surface that does not allow your boards or machine to sink into is a sign of cohesive snow. Move to a more sheltered location to avoid this problem. 

    (2/26/2025)

    A small natural soft slab avalanche is visible beneath the cornice.

    Photo: Mark Dundas

Avalanche Discussion

Two storms affected our area this week, resulting in 1-3 feet of snowfall that rests on a stout crust formed in late March. High pressure began building in the Flathead overnight and is expected to strengthen through the weekend. This week's cloudy, wet weather will be replaced by warming, drying, and mostly sunny conditions. With the sun high in the sky and over 13 hours of daylight, the sun can feel intense and produce rapid change in the surface snow. 

We expect a natural wet loose avalanche cycle to start today and increase in size and distribution through the weekend. This morning's cold temperatures will delay the onset of the wet snow instabilities, but as the day heats up, surfaces should become moist. At this time of year, even northerly aspects can receive sufficient solar radiation to be affected. This weekend's meltwater may percolate through the new snow, pooling on the crust and potentially triggering wet slab avalanches.

Developing meltwater may increase the chance of a glide crack failure as the weekend heats up. Many glide cracks expanded, and several failed, during the late-March wet storm. Cracks can be found on all aspects and elevations, but are concentrated on sunny slopes at mid-elevations.

Shifting winds and recent snowfall have built fresh cornices and expanded existing ones on various aspects. Warming temperatures through the weekend will weaken these features, allowing them to sag and potentially fail. A block tumbling down the hill could initiate a large wet loose or wind slab avalanche on the slope below. On sun-baked slopes, limit your time beneath these behemoths.

 

 

 

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