Avalanche forecast

Banner Summit

Sawtooth Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Avalanches large enough to bury you will be easy to trigger on many slopes today. Slides can be triggered from long distances away from steeper slopes, breaking well above you and cascading down to the slopes below. Avalanches that break into deeper weak layers in the snowpack will be very large and unsurvivable. Travel in and below avalanche terrain is not recommended.

Avalanche problems

  • Persistent Slabs

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

    Avalanches that fail on weak snow near the ground and wipe out the entire season's snowpack remain likely today. Slides failing on this layer will be unsurvivable. These will involve entire alpine bowls, with crowns spanning numerous aspects and wrapping around thousands of feet of terrain. Such slides can run down into flat terrain at valley bottoms, piling up enough debris to completely bury your house. You can trigger these enormous slides from the valley bottom. 

    The layer of weak snow that can produce these slides exists on all upper elevation slopes and many middle elevation slopes (those facing W-N-E). 

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1.5–2.5

    Large avalanches breaking 1-3 feet below the snow surface will be easy to trigger today and may continue to release naturally. These slides can break hundreds to thousands of feet wide and can be triggered from long distances away from steeper slopes. Even smaller slopes at lower elevations can make avalanches with a snowpack like ours. Expect to see and to be able to trigger avalanches in unusual locations today. 

    A widespread layer of weak snow developed during the December drought and was buried by a series of storms this week. This layer exists on almost all slopes. There are several layers of surface hoar here, in addition to very weak stacks of facets and facet + crust combos. Slabs that fail on this layer will be largest, easiest to trigger, and most destructive in areas where the wind has been at work building slabs. Thanks to the strength of yesterday's wind, this includes most slopes. However, even slopes sheltered from the effects of the wind are not to be trusted with a weak layer like this. 

    Avalanches that fail on this layer can break into the weak snow near the ground, producing very large, unsurvivable avalanches (see Problem #2 below).

    (1/11/2024) This large avalanche was remotely triggered in the Headwaters drainage. Ben and his partner on Thursday afternoon were over 100 feet away, on the opposite side of the ridge when they triggered this collapse and resulting avalanche.  This avalanche ran through some very hazardous terrain and was plenty large to bury a person.

Avalanche Discussion

Today's avalanches will be easy to trigger and will come in two sizes: large and unsurvivable. To make matters worse, you'll be able to trigger them from long distances away. Does that sound dangerous? Good, I'm doing at least a decent job of describing the world you'll head out into this morning. Let's keep the story going:

You park your truck and glance up at the thermometer. The skies are clear and it is 25 below 0 F...woof. Hop out, feel your nose hairs freeze, and get ready to fight the starter on your sled at least a few times. Do a beacon check with your partners while your engine warms up, tuck in all your layers and put on your warmest gloves... You are already in a dangerous environment and you haven't even left the trailhead.  Even minor inconveniences can turn into big problems on days like this.

Throttle away from the trailhead and watch the mountains slide by as you ride. There are many avalanches to be seen in the mountains above you. As you enter open meadows you can feel the snowpack collapsing underneath you, dropping you towards the weak snow buried by recent storms. In places you can see these collapses travel across entire meadows, shaking the fresh snow off the trees. You're glad that there aren't any steep slopes above you.

Riding further into the mountains the terrain narrows and steep slopes rise above the valley bottom. You can make avalanches here, large ones. Avalanches can be triggered from the valley floor, releasing a thousand feet above you and burying the road you are riding on. You know this, and you give the runout zones beneath steep slopes a wide berth.

Further in, you find some nice, low-angle meadows free of overhead hazard to play in. Temperatures warm slightly and skies start to cloud up as you burn through the fuel in your tank. Get stuck once or twice and keep that big grin plastered on your face. You find your eyes and your mind drawn towards some steeper terrain, but you remind yourself of the multiple layers of weak snow buried in the snowpack and the large avalanches they can produce. It's getting late, and you ride back towards your truck, tempted by the slopes that you avoided on the ride in. You reaffirm your commitment to not getting caught in an avalanche today and give these slopes a wide berth, just like you did on the approach.

Load your sled and set your compass towards home. Open the front door and tell your friends and family about the mind-blowing day you just had, still unable to wipe the grin from your face. It is dangerous out there, but we can still have a great time in the mountains. I encourage you to enjoy the fresh coat of snow, the morning sunshine, and the sound of your partner's laughter, all while steering clear of avalanche terrain today.

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