Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Dangerous avalanche conditions exist today. Natural activity is possible and rider triggered avalanches are likely in steep terrain on all aspects and all elevations. These avalanches could be large and propagate long distances across slopes. Avoid traveling in, near, or under avalanche terrain today.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–3

    Large hard slab avalanches are a real threat today. A widespread, well connected, and very weak layer of snow that formed during a month-long dry period in December has been overloaded by nearly 5 feet of snow with over 6 inches of snow water equivalent (SWE) since January 4th. Rider triggered avalanches in steep terrain are likely today. In the middle and upper elevations, avalanches could break 2 to 4 feet deep. Below 7,500’ slab depths will be in the 1 to 2 foot range. These avalanches continue to be triggered on all aspects (shaded and sunny) at all elevations. Slabs could be triggered from a distance, by the first rider, or even wait until the last person in your group is riding the slope to release. Rising temperatures today will increase the sensitivity of these slabs.

    Cautious route finding and conservative terrain choices are important today. Avoid terrain that is connected to avalanche paths and give runout zones a wide margin while traveling. This also means being aware of the terrain that is above you, as remote triggering is possible. For the time being, sticking to low angle terrain with little consequence is the best way to mitigate this problem.

    (1/20/2024)

    A large, wide propagating persistent slab avalanche that occurred yesterday day afternoon south of JHMR.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3.5

    Weak snow formed during a dry period in November persists at the base of the snowpack. This layer is now buried about 5 to 6 feet deep in the Tetons. It is at its weakest on the north half of the compass. Recent loading and warm temperatures are keeping this weak layer on the radar. These very large avalanches are most likely to occur when an avalanche triggered in the most recent snow steps down to weak old snow. Any avalanche involving the entire snowpack will be destructive and likely unsurvivable.

Avalanche Discussion

Although natural activity and obvious signs of instability such as cracking and collapsing have decreased over the past two days, avalanche conditions remain dangerous. Temperatures have been notably warm over the past 24 hours. Yesterday afternoon, temperatures at 9,000’ were hovering around freezing while low elevation weather stations reached nearly 40 °F. Temperatures are expected to be similar today, increasing the likelihood of triggering slab avalanches during the warmest part of the day. This is particularly true at low elevations where the snowpack is thinner and temperatures have been warmest. A very large, and wide propagating avalanche that was most likely remote triggered occurred yesterday afternoon just south of JHMR. Another report from Teton Pass yesterday described a large avalanche that broke when a person was walking around in flat terrain below the slope. These reports are evidence that the snowpack is currently very sensitive to human triggers. It is important to note that you may not experience any signs of instability until you trigger a large, destructive avalanche. Conservative decision making is warranted given the size and wide propagating nature of the avalanches that are currently being observed. 

Regions covered