Lawinenlagebericht

Seeley Lake

West Central Montana Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Veraltet — dieser Lagebericht ist 6 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

New and wind-blown snow on a weak snowpack is creating complicated avalanche conditions. Weak layers buried a foot or deeper could create large, unpredictable avalanches. You are unlikely to see obvious signs of instability, such as cracking and collapsing, before triggering an avalanche. The safest and best quality riding will be on low-angle slopes sheltered from the wind.

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1.5–3

    Multiple weak layers are buried in the upper 1 to 3 feet of the snowpack. These layers have produced many natural and human-triggered avalanches over the past ten days (click here to see observations). The largest of these avalanches have been in the Seeley Lake region.

    Weak interfaces exist on all aspects at middle and upper elevations, but change in character around the compass. Avalanches will be easiest to trigger on shaded northerly slopes where buried weak layers contain feathery surface hoar. Contrary to common thinking, avalanches may become easier to trigger as you drop in elevation to increasingly treed and sheltered slopes. On solar aspects avalanches may be more stubborn, but will be just as large and dangerous if triggered.

    You are unlikely to see signs of instability such as cracking and collapsing before you trigger a large avalanche. Importantly, you may be able to trigger these slides remotely — at a distance away from the slope that actually avalanches. Tracks on a slope do not indicate stability. To avoid this avalanche problem completely, you’ll have to avoid slopes over 30 degrees, as well as the flats below them.

    The snowpack in an wind sheltered area of the Rattlesnake, showing storms and weak interfaces since mid-January. The snowpack looks similar but deeper near Seeley.

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    In the past few days we’ve observed both human-triggered and natural wind slab avalanches, as well as extensive snow transport by wind. With moderate wind speeds and snow still available for transport, wind slabs will continue to build today.

    Look for blowing snow, drifts, and cornices as clues that wind slabs exist. Wind slabs feel like upside-down snow in localized areas. You are most likely to find wind slabs on the downwind sides of ridges, rollovers, and gulleys. With westerly winds we expect most wind slabs to form on easterly aspects. However, mountainous terrain can funnel wind in unpredictable directions. Keep an eye out for wind slabs on all aspects at upper elevations. To avoid this problem, avoid freshly wind loaded slopes over 30 degrees.

    (2/25/2026)

    This wind slab avalanche was intentionally triggered on Wednesday with some stomping along a wind-loaded ridge. Strong westerly winds were readily transporting the recent snow into sensitive slabs in wind-exposed terrain. This slab was thin, but broke about 150 feet wide on a NW aspect at 7,700'. We observed other similar avalanches that released naturally that afternoon.

    Photo: Ben VandenBos

Avalanche Discussion

The storm is over, but it’s left behind a snowpack ripe for human-triggered avalanches.

Heavy snowfall ended two days ago, just in time for winds to pick up. With persistent weak layers buried in the snowpack, avalanche hazard remains elevated. Even as storm snow bonds to the previous surface, weak surface hoar and facet layers remain below. We are still getting easy propagations in extended column tests on northerly aspects at upper and middle elevations. This is a clear sign of instability, and northerly aspects are a good bet for triggering an avalanche. On other aspects the sensitivity of weak layers varies throughout the terrain. Don’t let the drop to moderate hazard at middle elevations fool you – specific areas are still plenty dangerous.

Wind slabs are still forming at high elevations. Wind slab avalanches can step down and trigger buried weak layers, and are dangerous even on their own. Wind slabs can break wider than expected, and hard debris increases the chance of injury, especially where terrain traps are present.

Pay attention to the snow as it changes today. Wind can quickly load a slope, and slabs can become more sensitive as wind speed or direction changes. Southerly slopes will see sun, which could create small wet loose avalanches or roller balls.

If you get out in the snow, take a minute to let us know what you see. Your observations are a key component to an accurate avalanche forecast. Information about avalanches, the amount of new snow and wind, and riding conditions are all very helpful. Thanks in advance for your time, we appreciate you. Click here to access the observation submission page.

It has been a tragic last ten days in the world of the snow. At least 13 people have been killed in avalanches in the Western US. You can find more information here. Let's do everything we can to not add to that ghastly number. 

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