Lawinenlagebericht

Olympics

Northwest Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
3 · Erheblich
Waldgrenze
3 · Erheblich
Unterhalb
Keine Stufe
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Veraltet — dieser Lagebericht ist 3 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Dangerous avalanche conditions will develop in the eastern Olympics due to warmth and sunshine after a significant snowfall. Large wet loose avalanches could run far on steep, open slopes and you can trigger a slab as the snow consolidates. In areas with less recent snowfall, such as Hurricane Ridge, these hazards will be small in size and the danger moderate.

Lawinenprobleme

  • Loose Wet

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

    1-2 ft of snow likely fell in the eastern Olympics Wednesday through Thursday. Snow levels were near sea level. Morning sunshine will combine with rapidly moderating temperatures to destabilize low-density snow on sun-exposed slopes. Natural avalanches could be large on any sun-exposed open slope with a pre-existing snowpack. Reduce your exposure to sun-exposed slopes 35 degrees and steeper, particularly if those slopes are above you. These avalanches could run fast and far on a crust. Once the sun comes out, seek lower elevation slopes and colder, shaded aspects. Rollerball activity off rocks and cliffs gives you your cue. There may be enough snow to recreate at lower elevations now in the eastern Olympics. Remember, that "if there's enough snow to ride, there's enough snow to slide."

    In the Hurricane Ridge area, storm totals were closer to 6". Wet avalanches will be small, but consequential if they rake you through the shallowly buried terrain obstacles.

    Example: A natural wet loose avalanche on a sun-exposed slope.

    Photo: Zack McGill

  • Storm Slabs

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

    Observers didn't find much of a slab in the Hurricane Ridge area on Thursday. However, higher snowfall rates in the eastern Olympics may have formed storm slabs. Alternatively, warming temperatures could give the recent snow more slab-like properties. If you find more than 8" of snow above the most recent crust, you'll want to evaluate the slab properties before engaging with open slopes steeper than 35 degrees. These slabs like to fail where the slope rolls over. Slabs could run on the stout 2/11 crust, within a friable crust several inches above, or within gradually healing mid-storm layers. Jump on a few, small, representative test slopes to see if anything moves.

    Example: Storm slab avalanche on a steep, unsupported slope.

    Photo: Irene Henninger

Avalanche Discussion

We have confidence that dangerous conditions exist in the eastern Olympics and that portion of the zone is more in line with this forecast. Use the recent snow depths over the last firm crust as a gauge for the hazard in your local area. More than 8" of snow above the 2/11 crust in your local terrain, and you can probably expect dangerous conditions on Friday with the potential for avalanches to push into the large range. Less than the 8" threshold, avalanches will be smaller with a lower less risk of traumatic injury.

Observers at Hurricane Ridge on Thursday found an average new snow depth of 6". The snow was not showing slab-like properties. Cornices were sensitive along ridgelines, and an intentionally triggered cornice fall produced a small dry loose avalanche that didn't run far. The 6" of fist-density snow has a friable 2 cm crust below it (which includes a layer of small facets). You might find 1-3" of settled snow below that crust above the stout 2/11 crust. This crust represents a new ground in the terrain. There were no notable test results, but the small layer of facets might be problematic in areas with more significant new snow depths. Early season hazards remain significant throughout the Hurricane Ridge terrain. In many areas, the low-density snow barely disguises buried obstacles (trees, rocks) or bare ground.  Photos in the gallery.

NWAC may issue a gray "No Rating" for an elevation band when there is not enough snow to present an avalanche hazard.

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