Boletín de aludes

Flathead Range & Glacier NP

Flathead Avalanche Center
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Peligro de aludes

Fri
Alta montaña
2 · Moderado
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 7 months ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

It’s possible to trigger a dangerous avalanche on a weak layer buried 1-3 feet deep. Safer riding conditions—and the best chance for soft snow—exist on low-angle, shaded slopes above about 6,000 feet. Wet avalanche activity has likely peaked, but fresh roller balls and pinwheels are your cue to move to shadier terrain.

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–2.5

    Since January 7th, at least nine avalanches have failed on facets over a crust. Several were remotely-triggered from adjacent low-angle terrain, three occurred naturally, and one caught and carried a snowmobiler. Most were large enough to bury, injure, or kill a person. All occurred on steep, open, or sparsely treed terrain above 5,000 feet.

    With time and no additional loading, the likelihood of triggering one of these avalanches should slowly decrease, but the consequences remain the same. This problem offers little to no warning before releasing, and snowpack tests have been unreliable, even near recent avalanches.

    If you encounter soft snow without a stout crust on the surface, triggering a hard persistent slab remains possible. The safest option is to stick to low-angle terrain. If you choose to ride steeper slopes, choose smaller terrain free from traps– like cliffs, gullies, and large trees–ride one at a time, and keep eyes on your partners.

    This problem should improve with time, but patience is the prudent choice today.

    (1/7/2026)

    The slide that started us off back on 1/7. This large sker-triggered avalanche occurred on a steep east-facing slope at about 6300' in the Southern Whitefish Range. 

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–1.5

    The likelihood of wet avalanches is trending downward after several days of heat and sun, and with cooler conditions in the forecast. That said, temperatures remain relatively warm this morning, especially farther east. Clear skies overnight should have produced a solid refreeze on previously wet slopes. Any resulting surface crust will slow the onset of wet loose activity today. 

    Pay close attention to the snow surface. If you see snow shedding from rock bands, cliffs, or upper start zones, or if you begin sinking past your boot tops into wet snow, move to shaded aspects or lower-angle, disconnected terrain.

    Avoiding the persistent slab problem will also limit your exposure to most remaining wet avalanche hazards.

    (1/14/2026)

    Rollerballs and small wet loose activity on a steep and rocky, southerly slope. These types of features are where hazard could linger today as the sun heats the surface.

    Photo: Chris Gotschalk

Avalanche Discussion

Yesterday marked the peak of the recent multi-day warming across the advisory area. Based on observations so far, wet avalanche activity was rather limited in its size and impact. With little additional settlement in the past 24 hours, cooling temps, surface crusts, and wind-stiffened snow on many solar aspects, any remaining wet avalanche activity should be isolated and confined to steep, rocky terrain.

This shifts our focus back to the persistent slab problem. While the warm-up may have added a bit of stress to the snowpack, it likely did not change the problem in a meaningful way or allow for a different travel approach. Meltwater probably did not reach the Christmas Crust except in very isolated locations, so the underlying weak layer largely remains intact. The slab is now stiffer, meaning that while it may be slightly harder to trigger, any avalanche that does release could propagate more widely than the slides we’ve seen so far. We are hopeful that several more days of calm weather will allow this problem to slowly heal, but until the next loading event comes and goes without incident, it remains difficult to trust.

Prior to the warm-up, good riding conditions existed on most aspects above about 5,000 feet. That good snow is now likely limited to shaded aspects above roughly 6,000 feet, which may push riders into higher terrain. Keep in mind, we have very limited observations above 7,500 feet this season. While recent persistent slab avalanches have occurred mainly at mid-elevations, we assume weak snow still exists at upper elevations. Travel there demands conservative decision-making, especially given the consequences of larger terrain, as illustrated by a very large natural avalanche on Nasukoin.

A few final things to consider:

Temperatures remain warmer in the Flathead, where terrain favors longer-running avalanches—give big slopes a wide margin if you find wet snow surfaces.

Finally, there is a small chance that liquid water below the surface could reach a buried layer and could trigger a deeper slab avalanche. While unlikely, use extra caution below large, south-facing slopes. 

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