Bulletin d’avalanche

Elkhorns

Wallowa Avalanche Center
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Danger d’avalanche

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

Points saillants

Continued snowfall has created lots of soft powder snow, this soft snow lacks strength and will run downhill on steep slopes. Be on the lookout for loose dry avalanches (sluffs)  on all terrain steeper than 30 degrees. If you see fan-shaped avalanches or accelerating sluffs reduce your slope angles.

This forecast is sponsored by Magic Woodland Studio.

Problèmes avalancheux

  • Loose Dry

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

    Continued snowfall, cool temperatures, and light winds have created prime dry loose avalanche conditions. These dry loose avalanches (sluffs) can easily be triggered by the weight of a person or machine. With sun crusts underlying all this new snow these avalanches have a slick, firm surface to run on and may gain speed quickly.

    You are most likely to find these avalanches in steep (>30 degrees) wind-sheltered areas.  Exercise caution on slopes where these avalanches could take you for a ride into rocks, trees or push you into a gully or off a cliff. 

    (3/23/2023)

    Small skier-triggered Dry Loose avalanche on a  test slope  in the Northern Elkhorns.

    Photo: TG

  • Persistent Slabs

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

    The storm that began on Wednesday (3/22) buried a layer of surface hoar. This surface hoar was widely observed at the onset of the storm. No avalanches have been reported on this layer and reports from the Elkhorns and Southern Wallowas indicate it is hard to find in snow pits.

    At this time, the absence of avalanches and spotty distribution of the surface hoar layer is not sufficient evidence to ignore this avalanche problem. Before committing to slopes > 30 degrees, you should dig into the snowpack to check for the presence of buried surface hoar. If snowpack evaluation at this level is beyond your skill set, you should enjoy great snow on slopes < 30 degrees.

    Whumpfs, shooting cracks, and recent avalanches are all signs of this avalanche problem. If you hear, feel, or see these signs reduce your slope angles.

    (3/22/2023)

    This photo of surface hoar was taken in the Northern Wallowas at a ridge-top location at around 9000'.  Surface hoar was observed everywhere we traveled between 6000' and 9000'. The surface hoar, where present, will be a weak layer that could easily fail under the weight of new snow expected to arrive Thursday into Saturday. Surface hoar was also observed recently in the Southern Wallowas and Northern Elkhorn mountains.

    Photo: TG

Avalanche Discussion

Storm totals now exceed 12" since Wednesday (3/22). This storm started with wind sufficient to build slabs, buried a layer of surface hoar, and covered up melt-freeze crusts.  As the storm begins to taper today, the urge to step out into more consequential terrain will be present.  Many avalanche problems exist and uncertainty around the buried surface hoar level is high. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential.

Thank you for your observations and please let us know what you see out there today!

Régions couvertes