Avalanche forecast

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Sawtooth Avalanche Center
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Avalanche danger

Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You're likely to trigger a 2-3 foot thick avalanche on many slopes. Wind-drifted terrain is the most dangerous, but you could also trigger a slide in sheltered areas. Avalanches may be triggered remotely—from gentler terrain above, below, and to the sides of steep slopes.

Avalanche problems

  • Persistent Slabs

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

    What is it?  2-3 foot thick slabs overlie persistent weak layers (sugary facets, surface hoar, or crusts) on most aspects and elevations. Recently wind-loaded slopes with stiffer snow in the top couple of feet of the snowpack are most likely to produce large avalanches, but slopes sheltered from the wind are also suspect.

    Where is it?  The weak layer exists at all elevations, but slabs become thicker and stiffer as you climb in elevation. Shadier aspects contain the ugliest faceted layers. While the snowpack remains quite weak at lower elevations, some slopes are currently lacking the cohesive slab component of the avalanche equation (weak layer + slab + steep slope). 

    How can you recognize it?  You're likely to experience snowpack collapsing or cracking while traveling. These red flags are obvious signs of instability. Wind-loaded areas feel stiffer under your skis or sled and are more supportable; these areas are especially dangerous. The weak layers plaguing us are easy to identify when you dig a quick hole in the snow.           

    How can you manage it?  Sadly, avoiding slopes steep enough to slide is the only surefire way to manage this problem.Persistent slab avalanches are tricky. You could trigger them remotely (from gentler terrain above, below, and to the sides of steep slopes—explanatory video here) and they may break wider than expected or higher on the slope above you. 

     

Avalanche Discussion

You Can't Always Get What You Want

Over the past week, 36 of 39 field observations reported fresh avalanche activity or snowpack collapsing or cracking. That's a staggering percentage of folks seeing obvious signs of instability. Unfortunately, the ugly weak layers in the snowpack are not strengthening very quickly. We all want the snowpack to stabilize enough to safely sample the fresh snow in steep terrain, but we appear to be stuck in purgatory for the time being. 

Is there anywhere to get onto steep slopes and not worry about triggering avalanches? At lower elevations near Ketchum, Hailey, and Carey, S-SW aspects had very little snow cover prior to the big early December storm. There, the persistent weak layers are less worrisome. The downside: you'll be skiing or sledding on the ground in a snowpack less than 2 feet deep, and the chance of breaking A-arms or bones increases. 

While we "can't always get what we want" (safe powder turns in steep terrain), we can still "get what we need." By all means, get outside and enjoy the impressive early-season conditions on lower-angled slopes. Just remember there's a good chance you could trigger avalanches big enough to injure or bury you on many steep slopes.   

Regions covered