Lawinenlagebericht

Olympics

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Sat
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Veraltet — dieser Lagebericht ist 8 months ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

You can trigger an avalanche within wind drifted snow on steep smooth slopes, despite the lack of snow on wind-stripped slopes nearby. Use inconsequential test slopes to identify firm, punchy snow that might be reactive in drifts 6" or deeper. The avalanche danger will increase sharply if you ascend above the 12/18 crust. 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    1–2

    Wind slabs are building in size, extent, and reactivity above a complex of Mid December Crusts at or just above the ground. Although most of the snow is arriving on a cooling trend and gradually stabilizing as it accumulates, the same won't be true on wind-loaded slopes. In these areas, you can trigger drifts 2-3 ft deep that could take you for an unforgiving ride through barely submerged (or not yet submerged) early season obstacles. At middle elevations, ease around steep wind-loaded start zones or below corniced wind lips, where you expect to find drifts 6" or deeper. If you ascend further and find the 12/18 crust disappearing, avalanches could be large, widespread, and easy to trigger in your terrain. From that point onwards, avoid all lee slopes 35 degrees and steeper, particularly those with active windloading. Don't underestimate the added risk of the early season hazards as sharp obstacles amplify your risk. 

    Example: Blowing snow and firm pillow-like drifts are great clues to anticipate wind load slopes. 

    Photo: ONP Rangers

Avalanche Discussion

We're finally rebuilding a snowpack in the Olympics, and as the new snow piles up, avalanche concerns are back. The Olympic Mountains have plenty of smooth heather, grass, and shale slopes that don't require a lot of snow depth to enable avalanche danger, particularly on the lee sides of ridgelines where the snowpack thickens more rapidly.

Observations on 12/18 were limited to below treeline elevations on the Hurricane Ridge Road. 6" of fresh snow accumulated through early Friday at these elevations, before snow changed to a wintry mix and rain, touching off widespread rollerball activity. Despite the shallow snow depths, a cutbank shows a very small natural wind slab even at these elevations.  Around a foot of snow has accumulated at Hurricane Ridge proper. You're likely to find a complex of Mid December Crusts, with the last one buried 12/18 extending to around 5000-5500 ft before snow levels drop Thursday night. We're expecting an additional 4-7" of snow accumulation above the crust with plenty of WSW winds to redistribute the increasingly low density snow that falls into slabs you can trigger.

If you head out on Friday, recognize that we don't have any on-the-ground information about the middle and upper elevation snowpacks, so you could encounter poorly bonded interfaces, firm older wind slabs, or even slick, icy crusts on exposed slopes or beneath the snow surface. Move into the terrain with an assessment mindset, keeping in mind the added risks of the early season snowpack. At upper elevations, the recent snow may sit on bare ground, where it may be even easier to hit rocks, stumps, or other obstacles. At lower elevations, there is not enough snow to recreate around Hurricane Ridge, but there might be more snow in some other parts of the range. If you find enough snow to ride, you could trigger an isolated, small slab in exposed terrain at lower elevations.

The weather over the past few weeks has been extraordinary, with torrential rains, extreme winds, flooding, and landslides. Many communities are dealing with damage to homes, infrastructure, and businesses, stretching resources thin. These events have limited access to the mountains for all of us. State and local resources are working diligently to reduce the worst of these impacts. We can help by being respectful of local communities, obeying road closures, and heeding ski area uphill travel policies.

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