Boletín de aludes

Flathead Range & Glacier NP

Flathead Avalanche Center
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Peligro de aludes

Sat
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 3 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

You can still trigger a large and potentially deadly avalanche on weak snow buried deep in the snowpack.  Audible collapses are a clear signal to move off of, and out from under, steep slopes.  Further reduce your risk by limiting your travel above terrain traps like cliffs, gullies, or exposed rocks and trees. If your boards or machine sink into mushy snow, move to lower-angle terrain for a safer experience.

Problemas de aludes

  • Persistent Slabs

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

    Large (D2) avalanches and audible collapses were observed as recently as yesterday (Thursday). Whumpfing collapses are a clear sign that it is still possible for a person or machine to trigger an avalanche that fails 1-4 feet deep on buried weak layers. The problematic structure - weak facets over a hard crust - appears most developed on slopes facing east through south to west and near the Continental Divide. At low elevations, this hazard exists on roadcuts and other steep slopes with continuous snow cover. 

    The most reliable way to reduce your exposure to this hazard is by staying off of and out from under steep slopes. In the absence of clear signs of instability—like recent avalanches, or collapses—do your due diligence by digging into the snow and looking for faceted, “sugary” snow near a crust 1 to 4 feet below the surface. Riding a slope where you find this layer includes the risk of triggering a potentially deadly slide. 

    (1/25/2024) Recent slab avalanche in the central Whitefish Range.

  • Loose Wet

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

    Observations this week featured all the hallmarks of wet snow in these elevation bands: trees shedding snow, roller balls, and natural wet loose avalanches, some large enough to bury a human. Dense debris can make even small slides difficult to escape, especially on very steep slopes or in confined gullies where debris can pick up momentum.  Move to less steep terrain if you find your skis, board, or machine sinking into a wet snow surface.  

    Many stations at middle and upper elevations are currently at their coldest temperature since Friday, though daytime temperatures will once again climb to or above freezing.  Lower elevations have seen five days above freezing and are well worked over by wet loose activity.  The hazard of triggering a wet loose slide is generally decreasing compared to earlier this week.  

     

    (1/24/2024)

    The two wet debris piles are old and the one closer occured today (1/24/24). 

    Photo: Cam Johnson

Avalanche Discussion

The snowpack isn’t necessarily screaming at us, but it’s definitely still talking.

Yesterday (Thursday), a party in the central Whitefish Range reported a recent slab avalanche. This slide ran naturally and crossed a road where it piled debris over 8 feet deep. That’s plenty deep to bury a person and their machine. Meanwhile, a party in southern Glacier National Park encountered whumpfs during their ascent and adjusted their route to avoid steep, open terrain. Likewise, BNSF Avalanche Safety continues to document natural and triggered avalanches failing on depth hoar near the ground near Essex. These observations indicate that warm temperatures and incremental precipitation are still stressing buried weak layers.  When the snowpack is talking, it’s best to listen. Continue to evaluate terrain carefully where weak layers exist. If you’re uncertain where that is, dig into the snowpack to see what you’re standing on.

Generally, winds have been light and southwesterly with week. Outliers—like Aeneas Ridge in the Swan Range and Hornet in the Whitefish Range—have recorded sustained winds strong enough to drift snow. If you are traveling at upper elevations in an area favored by recent snow and wind, continue to evaluate terrain carefully. Look for signs of wind-affected snow, like a scalloped surface or dune-shaped feature along ridges, saddles, and other prominent terrain features. Find a less steep slope if wind-drifted snow cracks around your feet or machine. A small surface slide may potentially cause a larger, more destructive avalanche on a buried weak layer.

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