Boletín de aludes

Swan Range

Flathead Avalanche Center
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Peligro de aludes

Sat
Alta montaña
4 · Fuerte
Límite del bosque
3 · Notable
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

Feet of new snow. Winds gusting over 70 mph. Continued snow and moderate winds today. Very dangerous avalanche conditions exist. Large and very large natural avalanches are likely, and human-triggered slides are very likely. Avoid traveling in avalanche terrain. That includes valley bottoms well below steep start zones. 

With Aeneas Ridge weather station down, it's hard to assess conditions in the Swan Range. It also appears that much of the zone may have gotten more snow than reported at Noisy Basin. Please approach this zone cautiously. 

Problemas de aludes

  • Persistent Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1.5–3

    The tiger lurking in the alder is the potential for large to very large avalanches that break well below the snow surface on weak layers buried in late January and mid-February. This hazard is most widespread at upper elevations, where warming early this week did not cap it with a supportable, melt-freeze crust. It is isolated at mid elevations. 

    This week's storms are burying these layers deeper, where a rider's weight is less likely to collapse them. Simultaneously, they're increasing the load on them —and the potential size of any avalanches that release. Yet you can't tell which trend dominates on a given slope. Has the tiger has gone back to its den? Or is it well-camouflaged? 

    The most reliable way to reduce your risk of a mauling is to avoid traveling on or below slopes steep enough to slide. With more snow and continued winds today, leeward start zones near ridges are continuing to load, and slides that release in the recent snow can easily step down to the older weak layers, producing slides that involve enough debris to run well into brushy, dry valley bottoms. 

    (3/2/2026)

    Crown of a very large (D3) hard slab avalanche that was remotely triggered on Snowshed Mountain before this most recent-loading event. This slide was triggered where the weak layer was closer to the surface, and than propagated out, breaking up to 6' deep.

    Weak layers are buried even deeper now, and any slide on these layers would be big, nasty, and hard to make it out of.

    Photo: Michael Reavis

  • Storm Slabs

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

    A rash of rider-triggered slides in the Whitefish zone — including one accident — demonstrates that the new and drifted snow is reactive to a rider's weight. In the Swan zone, similar conditions exist today. Riders are likely to trigger slabs of new and wind-stiffened snow 1 to 3 feet thick on steep slopes at mid and upper elevations. These will be thicker, produce larger avalanches, and be more sensitive to a rider's weight on upper-elevation, leeward slopes. In this terrain, low-density snow may be camouflaging hard slabs formed Wednesday night and Thursday. 

    Low-angle slopes have excellent riding conditions right now. Stick to these — boondock in the trees, enjoy fast turns on gentle slopes, and stay out from under steeper start zones. Shooting cracks and recent slides are clear, unambiguous billboards with all cap letters shouting "Danger!"

     

    (3/12/2026)

    A snowboarder was caught and carried on this slab avalanche in plain view of Chair 5 at WMR. A very steep slope above terrain traps (very hard trees). The rider was not wearing a beacon and his partner did not have rescue gear. The rider is lucky to have walked away unscathed. 

Avalanche Discussion

Dangerous to very dangerous avalanche conditions exist across the region. Even small slopes have enough new snow to produce avalanches large enough to injure or bury a rider. And big, upper elevation slide paths hold large, thick slabs that can release on deeply buried weak layers, possibly triggered by smaller slides in the new snow. And the region will see more new and drifted snow today.

The best way to approach these conditions — and to come home so you can ride again tomorrow, next week, and next year — is to enjoy fast turns and boondocking on low-angled slopes that aren't below steeper start zones, especially those hundreds or thousands of feet above you where winds continue to top-load and cross-load steep terrain.

Allow me to be blunt, and speak from some hard experience. Getting caught and carried on a very steep slope (over 40 degrees) above terrain traps (large, hard trees) after you've walked past a recent slide when neither you nor your partner is carrying rescue gear, all in full view of a chairlift of people... that is NOT how to enjoy these conditions. I have written way too many accident reports that include similar elements. Many of those reports had very sad endings that left family and communities devasted. That is, however, what happened in the sidecountry around WMR Thursday. Minus the tragic ending, thankfully. I'm relieved they're ok. But luck is not a reliable, long-term strategy. Particularly on Friday the 13th. Please think about more than the moment in your decisions today. And ask your riding partners to do the same.

The terrain around WMR is avalanche terrain, regardless of whether it's in sight of a lift or you've bootpacked up there a hundred times. That includes Radio Towers, Hellroaring, and all the other short, hike-to runs. 

A note on today's forecast for the Swan Range — lots of uncertainty, especially about conditions on the east side of the range/ west side of the reservoir. Approach cautiously. 

Regiones cubiertas