Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
View on map

Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Open full map
Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Triggering a wide, 2-3 foot thick slab avalanche is possible in both sheltered and wind-loaded terrain. Today's storm will build fresh, sensitive slabs in windy areas by nightfall. You can reduce your odds of triggering these smaller slides by avoiding slopes with stiff, wind-drifted snow at the surface. 

Avalanche problems

  • Persistent Slabs

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

    Several days of heavy, dense snowfall, rain, and warm temperatures formed thick, meaty slabs on most middle and upper elevation slopes. Multiple crusts are buried in the upper 3 feet of the snowpack, providing possible failure layers for the slabs above. 

    Assume the slab + weak layer setup exists on all slopes. You may or may not experience obvious signs of instability—like snowpack collapsing or cracks shooting out from your skis or sled—before triggering an avalanche. 

    As you change elevation and aspect, or travel through different drainages, you'll see significant variability in the buried crusts. This uncertainty makes it challenging to accurately predict which slopes are trouble and which are safe to ski or ride. You may be able to trigger avalanches remotely—from flat terrain below, above, and to the sides of steep slopes. 

    Additional Discussion: Weak, sugary, faceted snow in the bottom part of the snowpack is now buried 2-5 feet deep on W-NW-N-NE-E-SE facing slopes at middle and upper elevations. Triggering a huge slide on these layers isn't as likely, but the resulting avalanche would be unsurvivable. You're most likely to poke this beast 1) where the snowpack is around 3 feet deep and  2) in windy and/or rocky areas where the snowpack depth is variable.  

     

    (12/20/2025) Large natural avalanche on Gladiator Peak in the Boulder Mtns. 

  • Wind Slabs

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

    Expect to find fresh wind drifts and slabs up to 2 feet thick in exposed, upper-elevation terrain. Watch for dunes or smooth pillows below ridgelines and cornices and on the sides of cross-loaded gullies. Cracks shooting out from your skis or sled are an obvious sign that you've found a wind slab. 

    Fortunately, the fresh wind slabs should be easy to spot and avoid. If you feel the surface snow getting stiffer, move to gentler terrain. Any wind slab you trigger has the potential to trigger the much larger Persistent Slabs as the wind slab avalanche moves downslope.

    (12/18/2025) Natural wind slab avalanches on a NE-facing slope near 8900' on Copper Mountain. Photo: Sawtooth Avalanche Center

Avalanche Discussion

Avalanche conditions are tricky. They vary from drainage to drainage and can change quickly as you round the compass or climb in elevation. Why? Over the past 10 days, we've added over 7" of water to the snowpack, more than the previous 2 months combined! This heavy precipitation fell with punctuations of extreme wind and wild temperature fluctuations that sent rain lines above 9,000' on multiple occasions. These rain-on-snow events saturated the snowpack in some middle and low elevation areas, which will ultimately be a good thing for stability once it firms up again.

Climbing in elevation separates these rain layers with layers of snow, building a complex array of crusts or possibly crust + facet combinations as you climb in elevation. The variability here adds a healthy dose of uncertainty. Underneath it all lurks the most prominent weak layer of the winter, a stack of facets that should not be forgotten about in areas where the snowpack depth is around 3' deep, or in steep, rocky terrain where the snowpack depths are variable. 

We have many questions left to answer, but some may have to wait. Another 3-day storm arrives today. This zone will get enough snow and wind today to begin freshening up the chance for wind slab avalanches in windy terrain. Enjoy the snow this holiday, but know that when conditions are complex, you can always choose simpler, lower-consequence terrain.

Regions covered