Bulletin d’avalanche

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
Voir sur la carte

Danger d’avalanche

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

Points saillants

Triggering a large slab avalanche is most likely on steep slopes facing the northern two-thirds of the compass, especially in the southern part of this zone where the snowpack is thinner. Sluffs involving the surface snow may release naturally on very steep, slopes basking in direct, unobscured sunlight. 

Problèmes avalancheux

  • Loose Wet

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

    Avalanches are most likely on very steep, rocky slopes receiving direct sun. These slides often initiate near the base of trees and rocks, gathering snow and growing in size as they move downhill. Rollerballs, or pinwheels, signify that the snow is heating up, and wet avalanches may soon follow. 

    While most will start small, they will be plenty large enough to knock you off your feet and carry you into unwanted terrain. Some slides have the potential to flank out into wider wet slab avalanches. Even small slides are consequential above terrain traps such as gullies, creeks, and thick timber. Plan your day to avoid lingering under steep, sunny slopes when the sun is out.

    (2/18/2025) Sun-induced loose snow avalanches on Boulder Pk in the Boulder Mountains. Photo: Sawtooth Avalanche Center

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–2.5

    Slabs that formed in early February rest above a variety of ugly, widespread, weak layers (facets, surface hoar, crusts, and combinations). Before triggering an avalanche, you're unlikely to experience obvious signs of instability like snowpack cracking and collapsing or whumpfing. Persistent Slabs can release in surprising ways and break much wider than expected. You are most likely to trigger a dense, 2-4 foot thick avalanche where:

    • The snowpack is less than about 4 feet thick—relatively shallower spots may exist where the wind frequently blows, and the slab is not uniformly thick.
    • Any part of the slope you are on or connected to is steeper than about 35 degrees
    • The slope faces the northern 2/3 of the compass
    • A smaller wind slab or loose snow avalanche overloads the buried weak layers

    (2/18/2025) A skier on Patterson Pk near Hailey triggered this large avalanche. After several turns on the slope, the slide broke above and around them. Thankfully, the skier was able to ski ahead and to the side of the slab. NW @ 8,050'. Photo: Sawtooth Avalanche Center

Avalanche Discussion

Very steep slopes basking in direct sunlight may still harbor enough ammo to release naturally with today’s continued sunshine. You can hedge your bets by avoiding lingering under these slopes soaking in the sun, or seeking cooler slopes if you find a mushy, wet snow surface. In alpine terrain, thin wind slabs may linger, watch for signs of wind-drifted snow or instability, such as cracking or collapsing. 

Triggering a large persistent slab avalanche remains possible—especially in areas where the wind frequently blows and the snowpack depth is variable. You are most likely to find trouble where the snowpack is less than about 4 feet deep. Outside of this zone, reports of recent avalanches in the Wood River Valley provide clear evidence that avalanches are still possible in similarly shallow areas in the southern portions of this zone:

  • February 6th: Natural avalanches on Patterson Pk (info)
  • February 9th: Skier triggered slide near Galena Summit (info)
  • February 9th: Skier triggered slide in Lake Creek (info, video)
  • February 16th-17th: Avalanches on Sun Mountain (info 1, info 2)
  • February 18th: Skier triggered slide on Patterson Pk (info)

These avalanches occurred on shaded (NW-NE-E) aspects where the snowpack was generally shallow, less than about 4 feet deep. Remember that tracks on a slope do not mean it's safe. Avalanches could be triggered after multiple people have skied the slope. 

 

 

Régions couvertes