Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Triggering a large slab avalanche is most likely on steep slopes facing the northern two-thirds of the compass, especially in the southern part of this zone where the snowpack is thinner. Expect loose snow avalanches in very steep, rocky terrain receiving direct sun.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

    Slabs that formed in early February rest above a variety of ugly, widespread, weak layers (facets, surface hoar, crusts, and combinations). Before triggering an avalanche, you may or may not experience obvious signs of instability like snowpack cracking and collapsing or whumpfing. Persistent Slabs can release in surprising ways and break much wider than expected. You are most likely to trigger a dense, 2-4 foot thick avalanche where:

    • The slab is less than about 2' thick—relatively shallower spots may exist where the wind frequently blows, and the slab is not uniformly thick.
    • Any part of the slope you are on or connected to is steeper than about 35 degrees
    • The slope faces the northern 2/3 of the compass
    • A smaller wind slab or loose snow avalanche overloads the buried weak layers (problem above)

    (2/18/2025) A skier on Patterson Pk near Hailey triggered this large avalanche. After several turns on the slope, the slide broke above and around them. Thankfully, the skier was able to ski ahead and to the side of the slab. NW @ 8,050'. Photo: Sawtooth Avalanche Center

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–2

    Recent snowfall has increased the odds of loose snow avalanches on all aspects. The largest of these are most likely on very steep, rocky slopes receiving direct sun. These slides often initiate near the base of trees and rocks, gathering snow and growing in size as they move downhill. Rollerballs, or pinwheels, signify that the snow is heating up, and wet avalanches may soon follow. 

    While most will start small, they will be plenty large enough to knock you off your feet and carry you into unwanted terrain. Some slides have the potential to flank out into wider wet slab avalanches. Even small slides are consequential above terrain traps such as gullies, creeks, and thick timber. Plan your day to avoid lingering under steep, sunny slopes when the sun is out.

    (2/18/2025) Sun-induced loose snow avalanches on Boulder Pk in the Boulder Mountains. Photo: Sawtooth Avalanche Center

Avalanche Discussion

Given the recent snowfall and wind, continue to look for and avoid steep slopes with obvious recent wind loading or signs of instability, like snowpack cracking or collapsing. Sluffing in very steep terrain is possible in dry snow on shaded slopes but is much more likely on any very steep slope soaking in the sun. Be aware of where even small avalanches may take you; terrain traps increase the consequence of being caught or buried.

Tuesday, a skier on Patterson Pk near Hailey triggered a large persistent slab avalanche. The slide broke above and around them after several turns on the slope. Thankfully, the skier was able to ski ahead and to the side of the slab. We've observed multiple avalanches in relatively thin snowpacks in and near the border of this zone since the first week in February:

  • February 6th: Natural avalanches on Patterson Pk (info)
  • February 9th: Skier triggered slide near Galena Summit (info)
  • February 9th: Skier triggered slide in Lake Creek (info, video)
  • February 16th-17th: Avalanches on Sun Mountain (info 1, info 2)
  • February 18th: Skier triggered slide on Patterson Pk (info)

These slides occurred on shadier NW-NE-E aspects where the slab was around 2' thick. Persistent slab problems can take a long time to heal. These slides and continued reports of collapsing in shallow snowpacks clearly indicate that triggering one of these slides remains a concern. Remember that tracks on a slope do not mean it's safe. Avalanches could be triggered after multiple people have skied the slope. 

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