Avalanche forecast

Tetons

Bridger-Teton Avalanche Center
View on map

Avalanche danger

Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous avalanche conditions will likely develop today. In addition to loose snow sluffs, there will be an increasing chance throughout the day for skiers and riders to trigger small to large pockets of newly developed wind slab in leeward terrain at the mid and upper elevations. While less likely to trigger, large to very large persistent slab avalanches will carry much higher consequences. These deadly slabs could also step down from the release of a wind slab. Monitor the amount of new snow that accumulates today, and take note of the wind’s ability to transport the new and available snow. Slopes that show signs of significant wind loading should be avoided.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Between 6 to 12 inches of light density snow fell in the past 24 hours, and another 6 to 9 inches could accumulate by this evening. Westerly ridgetop winds will also be on the increase, and newly developed wind slabs will gain depth and volume as the day progresses. These slabs are building on a variety of snow surfaces which include surface hoar, near surface facets, wind pack and sun crusts. By the end of the day, skiers and riders could easily trigger these slabs with depths ranging from one to two feet in steep, wind loaded terrain above 8,500 feet.

  • Persistent Slabs

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

    Persistent weak layers of faceted snow associated with the December 11th interface vary significantly across the landscape. Since yesterday morning, around a half of an inch of snow water equivalent has accumulated above these weak layers, and the overriding slabs will become more sensitive to failure as new snow and wind continue to add weight throughout the day. Skiers and riders could trigger these slabs with depths ranging from two to five feet above 7,500 feet. Previous tracks are not an indication of stability, and conservative terrain choices are the best tool to manage this hazard. With the exception of steep, isolated terrain features, the snowpack is mostly stable below 7,500 feet.

Avalanche Discussion

Mostly dry conditions are in store overnight and through midday on Monday as a transitory ridge of high pressure moves across the region. The next storm system is expected to begin impacting the area late in the day on Monday. Overnight lows in the mountains will remain in the upper teens before rising into the mid-20s in the afternoon. Westerly ridgetop winds will back to the southwest and decrease to 20 to 25 miles per hour.Dangerous avalanche conditions exist in the Teton and Southwest Trails forecast zones, and the general avalanche hazard is expected to remain Considerable on Monday. In the Tetons, skiers and riders could easily trigger small to large, recently developed wind slabs in leeward terrain above 8,500 feet, and small pockets of human triggered wind slab could be possible down south. In both areas, much higher consequences are associated with persistent weak layers buried deeply in the snowpack. On a variety of aspects above 7,500 feet, backcountry travelers could trigger large to very large, deadly slab avalanches failing on these weak layers. The snowpack below 7,500 feet has poor structure. If heavy snowfall or rain showers develop earlier than expected, small to large persistent slab avalanches could become a concern at the lower elevations.To the north on Togwotee Pass, skiers and riders have some potential of triggering large persistent slabs, and the hazard is expected to remain Moderate. Large triggers, such as snowmobiles or groups of people, are more likely to initiate one of these slabs, and previous tracks should not be taken as an indication of stability.

Regions covered