Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Avalanche hazard will rise throughout the day. Heavy snowfall, warming temperatures, and sustained winds will create dangerous avalanche conditions in the middle and upper elevations. Slabs will be most sensitive in wind affected, upper elevation terrain. In addition, it remains possible for riders to trigger deeper avalanches that fail on weak snow in the middle of the snowpack. Careful evaluation of the new snowfall as well as deeper weak layers will be important today. Conservative terrain choices are recommended.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Heavy snowfall expected today and sustained winds out of the south will form sensitive new soft slabs 8-18” deep at the middle and upper elevations. Expect slab depths to be deeper (2-3 feet) in areas where the new snow falls on wind slabs that were formed two days ago. Watch out for obvious signs of instability such as shooting cracks, collapsing, and “upside down” feeling snow, even in sheltered areas. Avoid steep, wind affected terrain today and practice safe travel habits.

    Several skiers were caught and carried by wind slabs yesterday. Click here to see the recent reports. Expect similar or worse conditions today.

    A wind slab on Taylor Mountain that occurred yesterday (2/4).

     

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    While trending less likely, it is possible for skiers and riders to trigger large hard slab avalanches failing on weak snow that persists in the middle of the snowpack. These slabs are 2-4 feet deep above 7,500’. Shaded aspects were least impacted by the recent warm weather. As a result, they are the areas where it will be easiest to find the persistent slab problem. Triggering one of these avalanches is most likely in locations where the slab is at its thinnest, making it possible for humans to impact the weak layer. Examples of terrain where thin spots exist include very steep, convex, rocky, and wind affected terrain features. New snowfall is stressing this weak layer and could make it more sensitive in locations where the overlaying slab is shallow. Avalanches involving new snow could step down to deeper layers in steep and sustained terrain.

    A persistent slab avalanche was triggered remotely two days ago (⅔) in shaded north facing terrain at 8,700’. This avalanche was triggered by the 7th rider on a slope. This terrain is a good example of where this problem is at its worst and highlights its difficult to predict nature.

    A persistent slab avalanche that was remotely triggered yesterday (2/3) south of Teton Pass. Crown visible through trees

Avalanche Discussion

The two avalanche problems that you may encounter today have distinctly different characteristics. Soft slabs are forming in steep terrain at the middle and upper elevations and will be most sensitive in areas affected by the wind. The likelihood of triggering one of these slabs is fairly high where they exist, however, they are also easy to predict. Cracking, collapsing, and other obvious signs of instability will be present. For the most part, the recent snow is falling on hard, slick crusts. Reports from yesterday suggest that slabs are not bonding well to this surface. As a result, these avalanches could propagate long distances and run fast. Rising temperatures throughout the day will make soft slabs even more sensitive. Because of this, sheltered terrain with significant new snow should be evaluated carefully.

The persistent slab problem is uniquely different. The chances of triggering one of these avalanches has decreased significantly, yet they are still possible and will present little warning before they release. This makes them much more difficult to predict and potentially more dangerous given the size and potential for propagation. Regardless of the type, getting caught in any avalanche can have severe consequences. We are managing two unique, but dangerous, avalanche problems today. Because of this, building in an extra margin of saftey to your plans is a good idea. Today is a good day to stay vigilant, dial back slope angles, watch your partners, and come home safe.

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