Bulletin d’avalanche

Tetons

Bridger-Teton Avalanche Center
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Danger d’avalanche

Sun
Alpin
3 · Marqué
Limite forestière
3 · Marqué
Sous la limite
2 · Modéré
Open full map
Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Triggering a large avalanche 2-4 feet deep in steep terrain remains likely today. Watch for thin rocky areas and wind affected snow. Warming temperatures throughout the day could increase the hazard on sunny slopes. Use caution around steep slopes and terrain traps.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2

    You are most likely to trigger a wind slab avalanche in exposed terrain at middle and upper elevations where recent snow and wind have built slabs 2-4 ft thick. This problem exists around exposed ridges, rocky features, crossloaded terrain features and gullies. Watch for shooting cracks and obvious pillows and drifts. Feel for changes in density around these features as you travel. The most recent snow has less wind effect and may be hiding wind slabs that were built on Wednesday and Thursday. Watch for wind slabs in exposed terrain even if visual clues are absent. Probe down with your pole to verify the existence of slabs.

    Additional Discussion: Storm Snow and warming temperatures

    There exists a density change in the top 16 inches of storm snow that is producing moderately planer hand shears. While storm snow has not settled into a cohesive slab, conditions could change rapidly when the sun emerges and snow begins to heat up.  Watch for changing conditions on middle and low-elevation steep southerly aspects. Collapsing and shooting cracks are sure signs of instability. Rollerballs on steep southerly slopes also indicate rapid warming. Be mindful of areas with large overhead avalanche hazard.

    (2/15/2024)

    Wind affected mid elevation terrain: Cornice fracture on the north side of a rock band at 8600 feet. Entrained a large amount of loose dry snow. (D2)

    Photo: Travis Baldwin

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1.5–2.5

    You are most likely to trigger an avalanche in a buried weak layer on thin, rocky steep slopes on west through north through east aspects. In the last few days, the weak layers that were buried on February 2nd received a large increase in loading. Weak layers are buried 3-4 feet deep, or deeper. We have not seen activity on this layer in some time and the likelihood of triggering is trending downward. With the large recent load, sensitivity may be currently heightened. Convexities and wind-affected thin areas should be carefully considered. Give yourself some margin around steep slopes today as we see how the snowpack adjusts to all this weight.

    The deep persistent slab problem was removed from the problem list today. We have not seen activity here in some time and it continues to get buried deeper. There are still persistent weak layers in the snowpack that are highlighted above that should remain on your radar, especially with lots of recent loading.

    A skier triggered avalanche that occurred two days ago (2/10) on the west side of the Tetons.

Avalanche Discussion

Today looks like it will be a beautiful day. Some morning fog in the valleys will give way to mostly sunny skies. It’s also a Saturday on a holiday weekend and one of the deepest days of the season. It’s going to be busy out there. On days like this, we often narrow our focus to a short list of important priorities like fat skis, face shots, and untracked slopes. Add your safety margin to that list. When you find yourself staring down that 35° slope, keep in mind that we just wrapped up a huge loading event and the snowpack is still adjusting. Consider the consequence if the slope avalanches - does the slope mellow out into low-angle meadows or does it roll over into the trees or dump into a steep terrain trap? Keep your head on a swivel and look for clues like recent avalanches or shooting cracks. Analyze the terrain and anticipate where the wind-affected snow is and where the shallow areas are around rocky slopes and convex features. Put all the puzzle pieces together and if the picture remains unclear, increase your safety margin and choose less complex terrain or slopes that aren’t as steep. Have fun out there.

 

Régions couvertes