Bulletin d’avalanche

West Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Thu
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Triggering avalanches is still possible in wind-drifted snow at upper elevations. Identify and avoid steep terrain where you find denser slabs sitting on softer snow below. Anticipate increased danger in alpine areas if winds are stronger than forecast.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    A new crop of wind slabs will build Tuesday night in above treeline areas. Danger may be greater on Wednesday around Baker and Shuksan due to stronger overnight wind speeds plus more deep snow available for transport.

    You are most likely to trigger a wind slab avalanche in steep terrain features that collect wind-drifted snow.  These might be below ridgeline on leeward slopes, on gully walls, and around cliffs and rock outcroppings. Look for changes in snow consistency and use visual clues like cornices and wind-scoured ridgelines to identify areas of wind slab. 

    Last weekend’s storms left us with a gift of plentiful deep, light snow. The downside is that same snow is very easy for the wind to transport into fresh wind slabs - and there is plenty of snow to go around. The question on Tuesday morning is how widespread, how deep, and how reactive are the new slabs. Use quick tests like hand shears, test slopes and simply stomping on small wind-drifted features to evaluate wind slab as you travel. 

    (12/13/2021)

    Cross loaded terrain features on Shuksan Arm

    Photo: Lee Lazzara

Avalanche Discussion

Strong winds overnight Monday with gusts to 40mph redistributed snow around the Baker Backcountry for the third day in a row. Numerous small and a few large avalanches were reported with avalanche mitigation work on Tuesday morning. Observers reported a stable snowpack in wind sheltered terrain with excellent (downhill) travel conditions. No avalanches in deeper new snow layers and/or involving either the December 8th or late November rain crusts have been reported. No observations have been submitted from other areas of the West North zone.

New snow amounts of 1-2” are expected overnight with wind speeds increasing again Tuesday evening. Wind should ease by Wednesday midday before a weak system moves through the area Wednesday night.

 

Régions couvertes