Lawinenlagebericht

Stevens Pass

Northwest Avalanche Center
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Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Kernpunkte

Approach steeper terrain with a cautious mindset, evaluating for things like shooting cracks, recent avalanches, and wet gloppy snow. Wind slabs may be found in unusual locations due to recent variable wind directions. Small loose wet avalanches may be initiated from steep slopes at low elevations where rain falls on dry snow. 

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1.5–2.5

    Winds have been flip-flopping back and forth from east to west in the past few days. Easterly winds most likely transported snow in many exposed locations as recently as Sunday. Intense wind drifting from westerly winds likely occurred Friday afternoon. Expect to find thick wind slabs on a variety of aspects because of this. Look for shooting cracks, and feel for strong over weak layering. These wind slabs may feel stiff, or hollow. Cornices could collapse if you go near them and trigger larger avalanches. 

    Use caution, and carefully consider each steep slope separately. Stay off of steep slopes that are actively being loaded by the wind. Recognize that avalanches could be triggered even after a person or two, or three have been on the slope. Very large, deep avalanches have recently occurred in the neighboring Snoqualmie and East Central zone. We don't have information about these in the Stevens Pass area, but that's enough information to keep me out of big, high elevation terrain features until we gather more information.

    (1/8/2022)

    Example wind drifting of snow from East winds at Snoqualmie Pass.

    Photo: Erik Olsen

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–1.5

    Light rain may contribute to moistening snown surfaces at low elevations. You would most likely trigger these in steep, open terrain. The deep layer of storm snow could also glide off rock slabs and grassy slopes.

    If you notice glopping and heavy, wet snow over dry snow surfaces, it's time to get off steep slopes.

    Roof avalanches will continue to pose a threat, so use caution and make sure children and pets stay well out from impact zones.

    (1/8/2022)

    Example loose wet avalanche.

    Photo: Dallas Glass

Avalanche Discussion

There is minimal access to most of the zone as Highway 2 is closed. Weather stations are down because of the lack of power. Uncertainty is high for these reasons, but we did get an observation from the 8th. Cleanup is expected to take some time from all of the avalanches and heavy new snow that have covered the road. On Friday WSDOT crews reported triggering D3.5 avalanches on the pass with control work. They observed natural avalanches in the D2.5 size range, some of which had occurred then, and some had occurred on Thursday. On Thursday, they reported multiple avalanches at least D3 in size hitting the closed highway west of Stevens Pass. In Tumwater Canyon, WSDOT reported over 208 debris piles on Highway 2 up to 15 feet deep, and several ran into the river. 10 of those slides were very large.

Before the storm, observers noted a couple of buried layers of large, faceted stellars and surface hoar. These layers are probably 3-5ft down at this point, and could be weak layers for slab avalanches.

Stay tuned as the saga of this storm unravels, and be sure to share your observations with us on the site here.

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