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

You can trigger an avalanche in steep terrain with slabs of recently wind drifted snow. Avalanche danger could be greater (Considerable) if you observe blowing snow and active, intense wind loading, especially around Highway 542 and the northeast portions of West North. 

Lawinenprobleme

  • Wind Slabs

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

    Wind slabs in steep convex or other unsupported terrain will be the greatest danger on Monday. Northeasterly winds could also build new slabs in addition to those left over from the latest storm. In general, avoid steep terrain where you observe active or very recent wind loading. Natural avalanches are unlikely, but could still occur if wind speeds and snow transport are much greater than expected.  

    In calmer areas use scoured snow surfaces, drifts and other visual clues to hunt down day-and-a-half old wind slabs. Use simple observations like test slopes and hand pits to see how well bonded they are to layers below. When in doubt just steer around steep features where you suspect wind loading. Utilize lower angled, more planar terrain where you are less likely to trigger an avalanche.

     

    Example of extensive wind transport in the Baker Backcountry from last season.

     

Avalanche Discussion

West North recieved 1' of new snow by Sunday morning with a bit more in favored locations. Winds gusting to strong overnight eased off by the morning and minor wind transport was noted during the day. Observers reported some, but not extensive, avalanche activity. Ski area mitigation work produced avalanches to D2 - mostly in wind loaded terrain. Small, shallow natural and human triggered avalanches were reported from wind sheltered areas. Forecast zones to the south recorded more wind through the day and heavily scoured ridges were noted near treeline.

The new snow over the weekend fell on a strong snowpack of rounded grains, melt forms and crusts. Weak, faceted snow and surface hoar that developed during November’s drought didn’t likely survive in most areas due to temperature inversions, strong sun and alpine winds. Rain preceding snowfall on November 22nd probably soaked whatever surface hoar and facets remined. 

Upper elevation terrain and areas farther east in the zone (that experienced colder temperatures and less/no rain) may still have pockets of weak snow existing under new snow layers. There is no information from less traveled terrain near the Cascade crest or alpine terrain in general. Be prepared to look for and assess this layer if you travel in these areas.  

Despite the latest storm - and more snow on the way this week - it's still early season and the snowpack is still shallow. Many hazards remain including exposed or barely buried trees and rocks, open creeks and other rugged terrain features.  

Abgedeckte Regionen