Bulletin d’avalanche

Logan

Utah Avalanche Center
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Danger d’avalanche

  • Alpin
  • Limite forestière
  • Sous la limite forestière
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Last night's storm created dangerous avalanche conditions and CONSIDERABLE danger in the backcountry. Avalanches in north facing terrain may fail on a buried persistent weak layer and could be triggered remotely, from a distance, or below. People are likely to trigger slab avalanches of wind drifted snow in exposed terrain, as well as soft slab and loose avalanches of storm snow on steep slopes at upper elevations.

  • People should avoid travel on or under steep slopes at upper and mid elevations.
  • Southerly facing and lower elevation terrain was bare or very shallow before last week's storm, so avalanches are unlikely in these areas, and the danger remains LOW.

Problèmes avalancheux

  • Persistent Slabs

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

    In north facing terrain above about 8000', some avalanches are likely to fail on a persistent weak layer consisting of sugary faceted grains.

    • Audible collapsing or "whumpfs" are a sign of unstable snow and of an active persistent weak layer problem.
    • Cracking in the snow surface is a sure sign of unstable snow.
    • Avalanches failing on this persistent weak layer could be triggered remotely, from a distance, or below.

  • Wind Slabs

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

    The CSI Logan Peak wind sensor at 9700' shows continuing strong winds blowing from the northwest this morning...

    • People are likely to trigger soft slab avalanches of wind drifted fresh snow at upper elevations where the winds are creating stiff drifts.
    • Avalanches could be 1 to 3-feet-deep.
    • Harder wind slabs formed before the storm and they are now buried by fresh snow and hidden from view.
    • Avoid recently drifted snow in and around terrain features like gullies, sub-ridges, and cliff bands.

  • Storm Slabs

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

    People are likely to trigger soft slab and loose avalanches of storm snow in steep terrain at upper and mid elevations in areas with previous snow cover.

    • Even small avalanches could be quite dangerous due to very shallow snow conditions.

Recent Activity

On Monday, backcountry skiers spotted a recent natural avalanche of wind drifted snow in the Grandfather Cornice Area of Cornice Ridge. The 2' deep and 100' wide avalanche occurred on a northeast facing slope at around 9300' in elevation.

Snow and Weather

Looks like about a foot of new snow fell across the Logan Zone overnight, with around that much on the sidewalk in West Logan as well. Winds shifted overnight and are still pretty strong, blowing out of the northwest and drifting the new snow in exposed terrain. Dangerous avalanche conditions exist, mainly in upper elevation terrain, with human triggered avalanches likely and natural avalanches possible. More snow is expected to accumulate in the next couple days in the Logan Zone, starting tonight.

***Sunny slopes up high and most slopes below about 8000' were bare of snow before last week's storm and now are still mostly rocks and bushes. Some were bare again yesterday due to recent warm temperatures and strong winds, others are only covered by a few inches.

Belle making her way up to the wind-swept saddle. The strong south winds were funneled through the notch and scoured all the snow down to rocks.

Additional Info

  • Always follow safe backcountry travel protocols. Go one person at a time in avalanche terrain, while the rest of your party watches from a safe area.
  • Check your avalanche rescue equipment, change your batteries, and practice often with your backcountry partners.
  • Be very careful, keep your speed down, and stay in control. Encounters with shallowly buried rocks or down trees in the early season have led to many season-ending injuries.
  • The Tony Grove Road is not maintained for wheeled vehicles in the winter season.

General Announcements

Get free batteries for your transceiver and a chance to win 1 of 10 Black Diamond Rescue Kits, 1 of 3 Mammut Barryvox transceivers, or 1 of 3 BCA Tracker transceivers. Stop at a participating shop, fill out our survey and get a free set of batteries. Don't need batteries, but still want a chance to win? Simply fill out the survey to be registered. Promotion runs through December 19.

  • Check out all the upcoming education classes and clinics HERE.
  • Please submit your observations from the backcountry HERE.

Régions couvertes