Bollettino valanghe

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

While not likely, you could trigger a large avalanche in wind-swept, rocky, alpine terrain. You could also trigger much smaller avalanches in recent drifts near ridgelines. Be alert to the possibility of loose snow avalanches (sluffs) on very steep slopes on the northern half of the compass.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    1.5–2.5

    Triggering a large persistent slab avalanche on weak, sugary facets buried deeper in the snowpack would take some bad luck. The video to the right/above describes this problem. You are most likely to find this scenario on slopes with all or most of the following characteristics:

    • Wind-swept alpine terrain, especially in the Pioneer, Boulder, and White Cloud Mountains
    • Steeper than about 35 degrees
    • Variable snowpack depths with areas less than 2 feet deep and/or rocks poking through the snow surface
    • Large, hard wind features 

     Don't expect obvious signs of instability (snowpack collapsing or cracking) before a large avalanche releases. Snowpack stability tests are of little use in situations like this. The only way to effectively reduce the odds that you trigger one of these slides is to avoid terrain that checks all or most of the "boxes" above.

Avalanche Discussion

Steering clear of old, hard wind deposits in the alpine is the most effective way to reduce your odds of triggering a large, destructive avalanche. While relatively minor, there are a couple of other scenarios to keep in mind as you prepare to head into the mountains:

  • Wind Slabs: Recent northerly winds have formed thin slabs. Some of these overlie weak facets or crusts—especially on SE-S-SW aspects—and may be more sensitive to triggering than you might expect. Wednesday, in the southern Sawtooths near McDonald Pk, I observed a wind slab that stepped down to one of these deeper weak layers (report). Wind slabs will be thicker and more widespread at upper elevations near Galena Summit. Look for wind-blown snow immediately below exposed ridgelines, on the sides of gullies or chutes, and near large terrain features.
  • Loose Snow Avalanches: The upper foot of the snowpack is extremely weak and faceted on some NW-N-NE-E facing slopes. On very steep slopes approaching 40 degrees, it won't take much to get surficial sluffs moving (photo). These may not be big enough to bury you, but they could knock you over and push you where you don't want to go. 

There are a lot of safe places to play, but don't get complacent. All of your standard safety protocols still apply. Continue to carry rescue gear, travel one at a time through avalanche terrain, and watch for signs of instability. Remember that even small avalanches can ruin your day in complex, high-consequence terrain. Before committing to skiing or riding a slope, think about where an avalanche could carry you. Could you get pushed over cliffs, through trees, or into creeks or gullies? Slopes with these terrain traps are inherently more dangerous than open slopes with a clean runout.

Regioni coperte