Bulletin d’avalanche

Tetons

Bridger-Teton Avalanche Center
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Danger d’avalanche

Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 9 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Areas of unstable snow persist and serious avalanche accidents are possible. Large slab avalanches could be triggered on avalanche prone slopes by the weight of a single person or after a slope has been previously crossed by other skiers or riders. New snow and wind will be loading the snowpack and increasing the sensitivity of these persistent slabs to human triggers. Shallow pockets of new wind slab may begin to form on leeward aspects along the higher ridge crests. Monitor snowfall intensity and the increasing load upon our problem layer. Increasing snowfall rates are possible, especially later in the day, and would increase the hazard. Collapses and shooting cracks are signs of instability. Expert terrain analyses skills, an understanding of our persistent slab avalanche problem and conservative terrain choices are essential for safe travel in avalanche terrain.

Problèmes avalancheux

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3

    At the mid and upper elevations cohesive slabs sit upon a buried weak layer of faceted snow that lies atop a hard crust. This problem layer and bed surface can produce human triggered avalanches two to four feet deep on a variety of aspects, but has been most active on north through east to southeast aspects. At the lower elevations, backcountry travelers may be able to trigger small slab avalanches in steep gullies.

Avalanche Discussion

A significant increase in the precipitation intensity is expected overnight. Warm air advection will keep overnight temperatures above freezing at the lower elevations. Snowfall amounts at the higher elevations are forecast to be 5 to 10 inches overnight with another 1 to 3 inches possible during the morning hours on Wednesday. Higher amounts in localized areas are possible. Cooler air will begin to move into the region during the day. Winds will be from the southwest tonight and back to the west during the day. Wind speeds are forecasts to be 25 with gusts from 35 to 55 miles per hour.Strong winds will create new soft slabs. The new snow will load our persistent weak layer. If the weather forecast verifies, conditions will become dangerous at the mid and upper elevations. Large natural and human triggered slab avalanches are possible. The persistent slabs will be bigger than they were during the last 10 days as their volume will be comprised of the snow from the previous cycle plus the new snow from this cycle. Careful assessment of the snow stability and terrain will be essential for safe travel in avalanche terrain. The general avalanche hazard is expected to increase to CONSIDERABLE above an elevation of 7.500 feet and be LOW below that elevation.

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