Bulletin d’avalanche

Eastside Region

Eastern Sierra Avalanche Center
Voir sur la carte

Danger d’avalanche

Wed
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

The avalanche hazard is expected to rise quickly this afternoon and into the evening hours as a potent and quick-moving storm enters the forecast area. Periods of very heavy snowfall and strong winds will create sensitive wind slabs on northerly and easterly aspects and add stress to buried weak layers. Evaluate snow and terrain carefully and be ready for increasing hazards as the day progresses.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Likely
    Taille
    1–2.5

    Rising hazards today will be largely driven by new snow accumulations drifting onto leeward terrain and is likely to occur later in the day as a strong storm enters the forecast area.  It will be crucial to conduct your own localized assessments and monitor snow totals closely. While older deposits have become stubborn you can expect the size and sensitivity of fresh wind slabs to increase very quickly as this storm enters the region. Our prevailing southwest winds will keep our focus on northerly and easterly aspects. Recent avalanche activity, fresh drifting, recent cornice growth, and hollow upside-down feeling snow are all clues that can help you identify and avoid areas of concern. Do your own localized assessments and be suspect of terrain features that encourage drifting such as the leeward sides of ridgelines, alpine couloirs, gully features, and cross-loaded depressions.

    (2/26/2023)

    Large natural wind slab avalanche. Released on the morning of 2/26 on a NE aspect at 8700'

  • Persistent Slabs

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

    Facet/crust combos buried in the upper snowpack continue to produce avalanches. At least 4 human-triggered avalanches were reported yesterday including two that were remotely triggered. While so far this problem has been largely isolated and resulting avalanches have been mostly small, the size and distribution of concerning areas may increase as new snow begins to accumulate this afternoon. Use caution in areas that had firm snow surfaces before the March 19th storm. Signs of instability include shooting cracks, collapsing, and remotely-triggered avalanches. However, it’s worth keeping in mind that this problem has proven tricky to pin down. Typical feedback may not be consistent and recent avalanches have caught people by surprise. Be careful around wind-loaded terrain and convex slopes. You can build a wider safety margin into your tour plan to limit your exposure to a problem that is difficult to assess.

    (3/27/2023)

    Investigating the crown of a persistent slab avalanche that caught and carried a rider on 3/26

Avalanche Discussion

While the calendar would suggest we have entered the magical time we like to call spring, the snowpack has different things in mind. This winter has been historically cold and we have seen record snowfall across the range. As we look down the barrel of yet another short-duration and high-intensity storm event it remains critical for the backcountry enthusiast to remain mindful. More skier/rider-triggered avalanches have been reported this week than we have seen all season including several remotely triggered avalanches and a couple that took people for long rides. Thankfully, no injuries have been reported yet. It is highly likely that this incoming storm will quickly lead to much more sensitive and widespread concerns.  We get it. After such a long season of elevated hazards and difficult access, we could all go for some of that stable and predictable Sierra magic right now. While we will get there eventually it's important to remember that we are still dealing with concerns more typical of mid-winter.

The snowpack has been talking. It’s up to us to listen.

As another impactful storm approaches, considerate travel choices and strategic parking will be appreciated as crews continue to manage the extraordinary snow load this season. With good coverage at lower elevations this winter, recent avalanches have been running further, impacting roadways and buildings in the communities of Mammoth, Virginia lakes, Mono City, June Lake, and Aspendell. It is important to practice good run-out awareness. Triggering an avalanche above infrastructure could have devastating consequences.  Remember that it often takes multiple passes to clear roadways and trailhead parking. Road crews are working overtime to allow access to communities that have been stranded by heavy snow, avalanche activity, and flood damage. Blocking snow drifts, travel routes, and snow piles makes it impossible for road crews to continue their work.

Régions couvertes