Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Last night's new snow and wind likely built a round of small, fresh drifts and sensitive cornices. These hazards may be dangerous on their own, but can also act as triggers for larger avalanches that fail on weak snow buried 2-3' deep. You can reduce your risk by steering clear of steep slopes with drifts or stiff snow near the surface. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    On Wednesday I experienced cracking in freshly formed wind-drifts near Galena Peak. Light to moderate wind and continued snowfall is expected over the next few days. Small, sensitive slabs and weak cornices will form in terrain exposed to the wind. These hazards are most likely in upper elevation terrain near and just below prominent ridgelines and in cirques beneath large cliff bands. 

    You can greatly reduce your risk of triggering a slide by sticking to terrain that's more sheltered from the wind. Keep in mind that even small slides can have big consequences if they drag you through trees or bury you in gullies or creek beds. 

    (2/17/2021) Small, sensitive pillows and cornices were observed along the west arm of Galena Peak.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    The weak snow buried near the ground continues to be the primary avalanche concern in this zone. While encountering a wind slab (described below in Problem #2) is more likely, any wind slab you trigger has a chance of "stepping-down" to the weak snow near the ground. Wednesday, I observed this overlap in avalanche problems on Galena Peak. Tuesday in Baker Creek, we saw multiple slab avalanches that were triggered by loose snow sluffs or small cornice fall. 

    Recent snowfall has hidden signs of wind events in places, making it more difficult to tell when you're on previously wind-loaded slopes. This fact has made many experienced skiers and riders think twice about entering consequential avalanche terrain, despite the gradually decreasing danger. 

    (2/13/2021) This avalanche was intentionally triggered by a skier stomping on the cornices/wind slab above. It failed on an E/NE facing slope at 9,700' above Titus Lake. The slide initiated in the stiff wind slabs that formed during last week's wind event and then stepped down to the weak snow near the ground as it traveled downslope.

Avalanche Discussion

In the past few weeks, snowpack characteristics have diverged significantly across our forecast area. In our northern zones, we are primarily dealing with "new snow" avalanche problems including fresh wind slabs created by new snow + wind (photo, photo, photo) as well as loose snow avalanches in very steep terrain. Less snow has fallen in our southern zones and an overall shallower snowpack has kept persistent weak layers or "old snow" avalanche problems at the top of our problem list. 

Recent storm totals and overall snow depth are highly variable across the Galena Summit & Eastern Mountain zone. The one constant tying these mountains together, and what makes these areas much different than our northern zones is the overall shallower snow depth. Most areas have snow depths of less than 4' deep and impacting weak layers of snow in the middle and lower portions of the snowpack remains a real possibility. We've continued to receive reports of snowpack collapsing from Baker Ck on up to Galena Pass. In the past two days, I've observed shallow, weak snowpacks near Galena Summit (observation) and in the Boulders (video). 

Given the same amount of snow and wind, the shallow, weaker areas in this zone will react much differently than the deeper, more forgiving areas in the Sawtooths. A quick spike in snowfall and moderate wind can quickly change the stability equation. Slabs like these can keep the threat of human-triggered slides elevated for several days after a storm. In addition, it's more difficult to separate new snow avalanche problems like wind slabs and cornice breaks from old snow problems like our persistent slabs. This is the case simply because smaller slides or cornice failures have a very real chance to "step-down" to more deeply buried weak layers, a scenario we saw play out on Titus Ridge last weekend (observation/photo). 

Regions covered