Bulletin d’avalanche

East Cabinet Mountains

Idaho Panhandle Avalanche Center
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Danger d’avalanche

Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

There are two avalanche problems to deal with right now. Persistent weak layers buried 8-12" deep are still showing the potential to create avalanches on north and east aspects at treeline. The other issue to keep in mind are the thin layers of wind slab building on those same aspects. To avoid the most risk of avalanches, avoid steep terrain over 30 degrees at treeline and above on north and east facing terrain. Anticipate a rise in avalanche danger this weekend as a modest amount of snow and southwest winds impacts the mountains on Saturday.

Problèmes avalancheux

  • Persistent Slabs

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

    During the past two weeks we have consistently found weakness in the upper 8-12" of the snowpack. In the East Cabinets we have been seeing a weak crust/facet combo and in the West Cabinets and Purcells we are finding buried surface hoar. Regardless of which weak layer you may find the take-home message is the same: you can get away with taking some risk right now regarding which terrain you choose to ride, until you find the wrong spot. The best riding conditions are on shady terrain between 5,500' and 7,000', this is also where large avalanches are possible. Keep your terrain selection conservative (less than 30 degrees) in these locations to stay out of harm's way.

  • Wind Slabs

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

    Yesterday at 7,000' in elevation observers found thin and sensitive wind slabs on north and east aspects. In terrain near open ridgelines it is likely you will find these windslabs to be thicker and easily triggered in steep terrain. With more wind and fresh snow rolling in on Saturday I would really be keeping this problem in your scope as it will likely grow and become more of a serious threat by Saturday afternoon.

Avalanche Discussion

Persistent slab is always the most devilish of avalanche problems. It lulls you into a false sense of security as it is often unreactive to triggers until you find a sweet spot. The issues however are very location specific and can be avoided. In terrain below 5,000' the weak layers are not much of a concern as they have been bridged by the freeze/thaw cycles we have been going through. Shady and sheltered terrain between 5,000' and 7,000' is really where the issue is, just dial back your risk meter and stay out of steep and open timber on the north and east aspects. Pay attention to the graphics in the avalanche problems because it is all about location right now if you seek to stay out of trouble.

Projecting into the future a bit we see more snow and wind coming on Saturday. The main concerns on my radar will be the potential for wind slabs to become thicker and more reactive during the weekend. The other issue I see will be the increase in snow load on our current weak layers. With more weight these surface hoar layers and weak crusts will be more prone to sliding. This will also result in a thicker and more dangerous slab.

Massive thanks to Nate Stephens and Mike Manion for covering field observations yesterday!

Régions couvertes