Lawinenlagebericht

East Slopes Central

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Fri
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 5 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Update 0630: Snowfall and winds were lighter than expected. Another round of snowfall and strong winds may create reactive wind slab at higher elevations. You could find surprising conditions near the crest where wind slab rests over a firm crust in alpine terrain. Use whumphing collapses and shooting cracks in wind loaded snow as the snowpack's way of telling you to stay out of steeper slopes nearby.

Lawinenprobleme

  • Wind Slabs

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

    A shot of new snow and strong WNW winds near ridgelines should add to previously formed wind slabs in similar areas. You could trigger surprising avalanches on upper elevation terrain or exposed slopes. Leeward terrain for the recent winds will be mainly on N-E-SE facing terrain, but you could find pockets of slab on all aspects. Look for signs such as wind stiffened snow, blowing snow, shooting cracks, and deeper drifts on leeward slopes. Steer around recent drifts and slabs on slopes steeper than 35 degrees. Use extra caution because these slabs may be resting on weak facets over a crust. These may be most problematic in alpine terrain near the crest that faces NW-NE, but keep your eyes peeled for shallow wind slabs even below treeline in some areas if you find 8" or more of new snow over the recent crust.

    If you see shooting cracks or get whumphing collapses, stick to slopes 30 degrees or less and put a large buffer of terrain between you and avalanche prone slopes. Monitor the bond between the recent storm snow and older crust layers. If you find weaker faceted grains on a crust or crumbly sugary snow over a crust, then all you need is a cohesive slab on a steep slope and it could avalanche.

    If the sun comes out, expect you could see small loose wet avalanches on steep sunny slopes. Rollerballs and moist snow are indicators these could run.

    (2/1/2022)

    Shooting crack on a wind-loaded feature at 5,800ft in the upper Salmon la Sac drainage.

    Photo: Ryan Minton

Avalanche Discussion

Forecaster Katie Warren was out in the Icicle drainage near the western edge of the zone on Wednesday, and found facets over a crust beneath the storm snow on north and east aspects between 4,500ft and 5,500ft. She observed lots of wind effect and blowing snow, though generally unreactive conditions. Recent storm totals are greatest near the crest. Observers reported around 16" of new snow at 5,000ft in the upper Salmon la Sac drainage on Tuesday, and 12" above Lake Wenatchee. Both observers found the storm snow was fairly well-bonded to older crust layers in these locations, but older faceted snow was not found at the interface. NW-NE aspects above 6,000ft or so are the most suspect slopes to hold this persistent weak layer. Drew found a crust/facet combo out at Holden, but there isn't enough snow on it to be problematic yet.

In the eastern portion of the zone new snow amounts are minimal and avalanche danger is isolated to shallow windslabs near leeward sides of ridges. Closer to the Cascade Crest in the upper drainages above Cle Elum, Leavenworth, Lake Wenatchee and Entiat you may find different conditions. Prior to the storm, observers found near-surface facets on a variety of shaded, northerly slopes and surface hoar on similar aspects below 4,700ft. Approach steep slopes with an assessment mindset and be ready to move to lower-angled terrain if you find reactive avalanche conditions. 

Abgedeckte Regionen