Boletín de aludes

Flathead Range & Glacier NP

Flathead Avalanche Center
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Peligro de aludes

Mon
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 6 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Today's warm precipitation and strong to extreme winds will load buried weak layers. Avalanches may fail naturally or be triggered by a rider, especially on wind-exposed slopes. Choose sheltered, low-angle terrain not connected to a steep slope for a safer, more enjoyable experience.

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    2–3

    Dense snowfall, rain, and substantial drifting are loading slopes harboring well-preserved buried weak layers. The threat of natural avalanches failing up to 5 feet deep remains on NW-NE-S aspects, especially in wind-exposed terrain. A rider's weight could trigger a large to very large avalanche, particularly in locations with variable snow depth where the weak layer is closer to the surface, such as wind-swept slopes or those peppered with rocks.  

    You will likely not receive signs of instability, such as collapsing or cracking, before triggering a slide. Due to the depth at which the weak layer is buried, snowpit tests may yield variable results. 

    Avoidance is the only sure bet when dealing with this challenging problem. Continue selecting low-angle slopes not connected to steep terrain. 

    (2/21/2026)

    This large hard slab avalanche was triggered by a rider on 2/21 east of Mathias Creek in the Central Whitefish Range. We presume it failed on a persistent weak layer of surface hoar on a crust (likely the JDL). 

    Ongoing loading is testing these weak layers and avalanches could fail naturally, or be triggered by a rider today.

    Photo: Anonymous

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–2

    An impressive wind event began Saturday and will last into Monday. Strong to extreme S-SW-W winds are transporting recent heavy, dense snow into thick slabs downwind of saddles and ridgelines, while also cross-loading gullies and mid-slope ribs. These features will thicken and become more widespread with elevation.

    Today’s drifting snow will point toward danger. Drumming sounds or collapsing indicate areas of a harder surface over softer snow. Cracks shooting away from your feet or machine confirm you have found a sensitive slab. Growing cornices may fail, triggering a slide on the slope below. 

    The terrain being loaded by today’s winds is the same terrain that harbors persistent weak layers. A small surface slide may trigger a larger, destructive avalanche, described in our Persistent Slab problem above.

    Choose low-angle slopes sheltered from the wind for better snow quality and safer conditions. 

    (3/7/2026)

    Strong southwest winds transported recent heavy, dense snow throughout Saturday. Winds increased overnight and will remain elevated on Sunday, drifting snow onto leeward slopes. 

    Photo: Mark Dundas

Avalanche Discussion

Beneficial moisture has fallen over the past four days, with 1.5 to 3.7 inches of water recorded. A High Wind Warning is in effect and will impact the Flathead through Monday, with strong to extreme winds (image) transporting recent dense snowfall onto slopes with buried weak layers. 

The frequency of reported avalanches has tapered, but the poor snowpack structure remains widespread. FAC staff's recent field days in the southern Whitefish Range (observation, observation) noted no new avalanches or signs of instability, but alarming results from snowpit tests. 

I traveled to Rescue Creek in the Flathead Range yesterday (Saturday). The majority of the terrain in this zone has remained unexplored this season due to the difficult access caused by the minimal low-elevation snowpack. I had low expectations entering the day, but was surprised at how thin the snowpack is (image). Unfortunately, it appears much of this zone won't be available for spring riding due to the exposed world-class alder fields that must be navigated on the access routes.

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