Lawinenlagebericht

West Slopes North

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Tue
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Open full map
Veraltet — dieser Lagebericht ist 4 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Steep rollovers, complex features, and wind-loaded terrain could still avalanche with a human trigger. We're coming out of a stormy period and the snowpack is slowly strengthening, but we still have a lot of uncertainties. Avoid large, convex slopes, high consequence areas, and locations where you can identify wind drifting on steep slopes. 

Lawinenprobleme

  • Storm Slabs

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

    Your main avalanche concerns are on steep, unsupported terrain where residual storm snow instabilities may be present, and on steep, wind-loaded slopes. Natural avalanches and reports of whumphing and easy failures during and just after the storm slowly shifted to harder test results and fewer signs of instabilities as the snow settled. We are still concerned about higher consequence areas and larger slopes, especially as you make your way towards above treeline elevations, where it may take more time for the storm instabilities to settle out. 

    Steer clear of steep, unsupported terrain or steep rollovers on Monday. Pay attention to snow surfaces, noting whether the snow gets thicker, or heavier feeling, which might help you determine whether wind loading has occurred in that area. Search for ripples or wind sculpted snow, and obvious clues such as long shooting cracks. Avoid steep slopes where you encounter these conditions as well.

     

     

    This is an old photo of a large avalanche on the Shuksan arm in the Baker backcountry. Note the unsupported nature of the slope, similar to an avalanche you could trigger on Monday.

    Photo: Liza Kimberly

Avalanche Discussion

Sluffs, or small dry loose avalanches might occur naturally or with a human trigger in steep areas where low density snow exists. Stay aware of them if you enter steep terrain. With clear skies upon us, steep sunny slopes may moisten and you could see rollerballs or small wet loose avalanches running.  As the snowpack gets deeper think about tree wells and snow immersion suffocation (SIS). Remain alert to this very real hazard when traveling through deep, unconsolidated snow and near trees, and check out the film below for more information about it. The knowledge presented in this film could possibly save your life. 

Before the storm on Friday, an observer reported triggering a small avalanche in an open meadow below treeline. You can read the observation HERE. The observer found feathery crystals, which were likely surface hoar, below the 40cm thick slab. Surface hoar was also found in a pit dug by a Pro 1 avalanche class in the Baker backcountry at around 5000ft, buried almost 3 feet down on a NE aspect on Sunday. They got a propagating extended column test (ECTP28) result on the layer, indicating that it might take a lot of force for the layer to be affected, but if it fails, it could propagate, resulting in an avalanche. This was found in one pit amidst several they dug. We don't know much about this layer right now, and most information we've gotten from it has been inconsistent. However, several zones are finding this layer, and a few avalanches have been reported as failing on it so far. 

Abgedeckte Regionen