Avalanche forecast

Snake River Range

Bridger-Teton Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Dangerous avalanche conditions exist. Triggering avalanches up to 2 feet deep will be likely in steep wind loaded terrain in the mid and upper elevations today. Natural avalanches will also be possible. Sticking to lower angle terrain and avoiding being in the runout of avalanche terrain will be critical today. Continued snowfall and wind will make triggering more likely as the day progresses.

Avalanche problems

  • Wind Slabs

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

    Over the last 24 hours the Snake River Range has received 10-12” of new snow accompanied by moderate winds out of the southwest and west. Steep wind loaded starting zones in the mid and upper elevations will be the most likely areas to trigger an avalanche today. In the lower elevations expect to encounter isolated pockets of slab up to 1 foot in depth in steep terrain. Avalanches will be large enough to injure and/or bury a person. Cautious route finding and conservative decisions will be important today. Be on the lookout for obvious signs of instability such as recent avalanches, shooting cracks and whoompfing. These are clues that should steer you towards lower angle terrain. Give yourself a wide berth and be aware of the terrain above, as avalanches have the potential to run long distances.

  • Persistent Slabs

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

    Weak layers that formed in early December remain a lingering problem today. These layers are now buried between 1-4 feet deep. Reactivity has been low recently, but the potential exists for these layers to reactivate with the additional load. Avalanches involving the new snow have the potential to step down to these deeper layers, especially in upper elevation in terrain on the north half of the compass. While this is a less likely problem than avalanches involving the new snow, the consequences are high.

Avalanche Discussion

New snow over the last 24 hours has created instability in the upper snowpack. The temperature trend so far has been favorable, in that there has been a steady decline overnight. This will lend itself to generally “right side up” conditions this morning. Exceptions to this will be found on wind loaded slopes. It is in these areas where triggering will be most likely. With more snow on the way, expect slabs to grow in depth and surface area as the day progresses.

Weak layers that formed in early December were overloaded by a storm cycle in mid December. As a result there was an avalanche cycle that occurred Dec 16-18th. Since that time, there has been a period of warm temperatures (Dec 21-23). This period allowed for the strengthening of these layers. Despite this improvement, snowpit tests have shown the lingering possibility of avalanches on these layers. Between Dec 23 and 24th, light snowfall accumulated and bonded well to the underlying layers. Beginning yesterday, snowfall has increased in intensity, introducing more rapid change to the snowpack. The deeper weak layers will be tested by additional loading in the coming days. The exact tipping point for these layers is yet to be determined. It will be important to dial back terrain choices today and continue that practice through the weekend in order to avoid involvement in large destructive avalanches.

Regions covered