Boletín de aludes

Whitefish Range

Flathead Avalanche Center
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Peligro de aludes

Sat
Alta montaña
4 · Fuerte
Límite del bosque
4 · Fuerte
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó 5 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Large avalanches have occurred every day this week. Continued warm temperatures and rain are causing very dangerous conditions. Avalanches may slide in the wet surface snow or break on buried weak layers. Travel near steep slopes is not recommended.

An Avalanche Warning is in effect through Saturday morning.

Problemas de aludes

  • Loose Wet

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

    Recent warm temperatures and rain guarantee you will encounter wet snow. Slides are most likely on steep slopes where your feet or machine sink into mushy surface snow. This includes heavily treed slopes. 

    Even small surface slides have the potential to trigger larger avalanches on buried weak layers (See Persistent Slab Problem)

    (3/19/2026) Mar 18, 2026: Recent wet loose avalanche on Paola Ridge. Photo: Adam Clark

  • Cornices

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–3

    Last weekend's snow and wind grew impressive cornices along alpine ridges. Sustained above-freezing temperatures and rain have weakened these overhanging ledges of snow, and failure is increasingly likely. Tumbling chunks of snow can cause large avalanches to fail on buried weak layers. Stay well back from the edge if traveling along ridgelines. 

    (3/15/2026)

    Large, overhanging cornices command respect when traveling next to or under. Rain and warm weather have put extra stress on an already large and heavy trigger for avalanches on the slope below.

    Photo: Meg Killen

  • Persistent Slabs

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

    Weak layers are being stressed by rain and warming. Avalanches can break thousands of feet wide and 5+ feet deep. Small slides or tumbling cornices are effective triggers for buried weak layers. Stay FAR away from steep slopes to avoid encountering one of these devastating slides.

    Wet Slab: Rain and meltwater are penetrating into the snowpack. Water can weaken bonds and cause slabs to fail more easily on buried weak layers. 

    (3/17/2026)

    A very large, destructive slab avalanche that failed on buried persistent weak layers on the E aspect of Nyack Mtn. 

    Photo: Michael Reavis

Avalanche Discussion

Observations from this week highlight variability in the advisory area.  Josh and Guy traveled to Link Mountain in the Central Whitefish Range. Their pit at 6000 feet revealed that recent rain and meltwater had only penetrated 2 to 4 inches deep. Meanwhile, Lydia and I visited Tunnel Ridge in the Flathead Range, where we found water had reached 6 feet below the surface at an elevation of 5800 feet. Earlier this week, Blase and Cam found water roughly 2 feet deep in the Swan Range.  Although parts of the region have seen different degrees of warming and rain, the end result is the same: avalanches are occurring in wet snow and on buried weak layers.

Most avalanche activity since last weekend's storm has been size D1-D2.5. BNSF avalanche safety documented the fallout in John F. Stevens, including a natural D2 slab avalanche that failed yesterday (Thursday) afternoon. A few larger (D3-4) avalanches have been reported on Nyack in the Flathead Range, and Sixmile in the Swan Range. 

 

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