Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Wet snow avalanches are possible in steep, rocky terrain receiving direct sun—be wary of traveling on or below these slopes, especially later in the day.  Cornices are large and may be unstable—give them a wide berth. Triggering a large slab avalanche is unlikely, but if you were to find trouble, it would be on steep slopes facing the northern two-thirds of the compass, especially in the southern part of this zone where the snowpack is thinner.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2

    Loose snow avalanches are 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 may will grow large and dangerous or push 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.

    (2/26/2025) Small natural wet loose avalanches in the Boulder Mountains. Photo: Sawtooth Avalanche Center

  • Persistent Slabs

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

    Slabs exist above widespread, weak layers (facets, surface hoar, crusts, and combinations). Persistent Slab avalanches are most likely in the thinner snowpacks of the Pioneer and Boulder Mtns in the southeastern part of this zone. Before triggering an avalanche, you're unlikely to 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 snowpack is less than 4 feet 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

     

    (2/26/2025) Large slab avalanche on Boulder Peak, Boulder Mountains. SE @ 10,000'. Photo: Sawtooth Avalanche Center

Avalanche Discussion

Any thin surface crusts that formed overnight will break down quickly, following the path of the sun—E and SE in the morning and S, SW, and W in the afternoon. If you are traveling on a frozen snow surface, the likelihood of finding wet snow problems is low. However, once these crusts break down, the likelihood of human-triggered slides will increase greatly. Many slopes have shed over the last few days of warm temperatures, and signs of instability like rollerballs, pinwheels, and natural slides may not be obvious. A mushy, wet snow surface indicates that stability is deteriorating, and it is time to seek shadier slopes. Plan your day to avoid traveling on or below steep slopes basking in direct sunlight, especially later in the day when temperatures and sunshine are at their peak. This zone harbors the most craggy terrain, acting as "solar ovens", and will ramp up the intensity of today's sunshine. 

Cornices are large and may be unstable. On Tuesday, we easily triggered a 200' wide and up to 8' thick section of freshly formed cornice. Warming temperatures may cause overhanging cornices to sag and fail. Limit time beneath these features and give them a wide berth when traveling along ridges. 

Triggering a large persistent slab avalanche is unlikely. If you were to find trouble, it would be in the shallower, wind-swept southern portion of this zone where the snowpack is thinner (less than about 4 feet). While this southern portion of the zone harbors the shallowest and likely highest chance of triggering a large slab avalanche, don't rule out the possibility of finding trouble elsewhere. We have observed a couple of very large slab avalanches in the Boulder Moutains that likely happened following a strong wind event on Monday night. 

Regions covered