Bulletin d’avalanche

Olympics

Northwest Avalanche Center
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Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

A nice sunny day with good visibility should help you manage a couple of specific avalanche issues. You may encounter generally small natural wet avalanches from steep southerly slopes. At mid and upper elevations, be leery of smooth pillow-like drifts formed by the wind this week.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    Sunshine and a few inches of recent snow will help make loose wet slides the most in-your-face avalanche concern on Saturday. Easy to recognize clues like snow shedding from trees/rocks and new rollerballs will help you anticipate the developing hazard. Expect loose wet avalanches to follow on similar slopes. 

    When you see these observations start paying attention to the terrain above you. Limit the time you spend on or underneath steep sunny slopes. While most of these slides should stay relatively small, some of them could entrain enough new snow to take you for an unwanted ride.

    (2/9/2023)

    This natural loose wet avalanche occurred during Thursday's (2/9) sunny and warm weather. 

    Photo: Sam Siemens-Luthy

  • Wind Slabs

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

    Reports from Hurricane ridge indicate a few small wind slabs exist near ridge crest and below cornices (all the usual spots). Fortunately, their smaller size should make them easier to manage. Use clues like sharp drifts, scoured slopes, and fresh cornices to help you anticipate potentially loaded slopes. Then steer around smooth pillow-like drifts by using lower angled or less wind-affected snow. 

    In some locations, these slabs could sit on a crust (2/9). This may allow them to trigger relatively easily and run quickly. While they should be generally small and shallow, don’t let them knock you off your feet in high consequence terrain.

    (2/9/2023)

    Cornices and scoured slopes are great clues to help you anticipate possible wind loaded slopes. 

    Photo: Sam Siemens-Luthy

Avalanche Discussion

While we think the danger will reside in these shallower snowpack layers, there is one lingering question. On northerly aspects, our NWAC observer and NPS rangers found a facet-crust layer at the base of this past week’s snow. On Thursday, snowpack tests repeatedly failed and propagated across large columns. While we haven’t heard of any avalanches at this 2/3 interface, it’s definitely on our radar. Saturday’s weather isn’t likely to wake it up. However, you may trigger this deeper weak snow with a larger trigger (cornice/other avalanche) or in rocky complex terrain. 

Saturday will be a bit of a transition for the mountain snowpack. Recent wind slabs should continue to heal even as sunshine creates new wet hazards. These nice days are often the times we seek to head into higher terrain or onto bigger objectives. These are the same locations we have less data to support the forecast. 

Observations from Friday indicated 6in of new snow greatly improved travel conditions at Hurricane Ridge. This new snow is well bonded to a thin breakable crust (2/9) that formed on Thursday.

Régions couvertes