Bulletin d’avalanche

Whitefish Range

Flathead Avalanche Center
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Danger d’avalanche

Tue
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 6 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Tricky avalanche conditions exist. You can abruptly ride off stable slopes and into terrain where you're likely to trigger large, dangerous avalanches. Plan your day to avoid steep, shaded slopes at mid and upper elevations. When you're riding, stick to terrain with dust-on-hard-to-sidehill crusts and pay careful attention to aspect. 

The avalanche danger will rise overnight and Tuesday as a significant storm loads buried weak layers with new and wind-blown snow.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    Scary Moderate - tricky conditions where you won't see many obvious signs of instability until you trigger a large, dangerous avalanche. Spatial variability compounds the hazard. Slabs may be less sensitive on some slopes, lulling you into complacency or a sense you've outsmarted the dragon. Really, you may have just gotten lucky.  

    Conservative terrain choices remain the most straightforward, reliable way to mitigate this hazard. Stick to slopes with a few inches of snow on a stout, refrozen crust. These are slopes where it can be difficult to sidehill. The hair on your neck should go up on slopes where your track or skis start to punch through a crust 2 to 4 inches below the surface. This transition can be abrupt. 

    A weak layer buried 10 to 15 inches deep remains the primary avalanche threat. This layer consists of weak facets and large, preserved surface hoar. It is often forms a distinct grey stripe or sits just above or below an obvious crust.

    We had no reports of triggered slides or shooting cracks Sunday, but one report of whumpfing on an upper elevation ridge in the southern Whitefish Range. Snowpit tests are still showing propagation, though columns are failing with more force. Though it may be slowly stabilizing, it remains a hazard on many, if not most, steep shaded slopes without a supportable crust.  

    (2/15/2026)

    The thick, grey stripe is the buried surface hoar that's sensitive a rider's weight. It has been reported as high as 7200 feet. 

Avalanche Discussion

Would I be surprised if a rider triggered a large, dangerous avalanche on a steep, shaded slope today? Would I be surprised if they didn't? Nope, in both cases. Can I tell you which shaded slopes will slide and which won't? Also nope.

That is Scary Moderate. It's not a formal rating, though it's a forecaster's nightmare. Human triggered avalanches likely on specific slopes; natural avalanches unlikely. You can ride all day with no signs of instability, or walk into an avalanche dragon with no warning. 

Avoid all steep, shaded slopes at mid and upper elevations. That may seem overly broad, but it's the best way to account for the uncertainty and variability. 

If southwesterly winds pick up today, blowing snow may build some small, thin wind slabs on steep slopes near ridgelines. These may not pose much of a threat in an of themselves. They will, however, add load to the same slopes that harbor the Persistent Slab problem. Yet another reason not to travel on or below steep, shaded start zones. 

The snow that fell Friday and Saturday is loose and prone to sluffing on steep slopes. There's not much of it, however. So triggering loose snow avalanches large enough to injure or bury you is a threat only on isolated slopes. Turn out of any sluff, particularly on slopes where it's runnining on stout crust.

 

Régions couvertes