Bulletin d’avalanche

West Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Wed
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
Sans niveau
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Périmé — ce bulletin a expiré 8 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Over a foot of snow will arrive by the end of the day at mid and upper elevations. If you're able to avoid road closures and make it into the mountains, choose lower-angle terrain away from large steep slopes, where several inches or more of soft snow exists, especially at upper elevations. Wet avalanche activity will increase as the day progresses and freezing levels rise. 

Problèmes avalancheux

  • Storm Slabs

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

    Expect large, dangerous natural and human-triggered avalanches on Tuesday. At upper elevations, a slick crust may exist beneath one to two feet of snow, making fresh slabs more prone to sliding. It’s a good day to stick to sheltered, lower-angle slopes and avoid traveling beneath steep terrain. 

    Wind-drifted areas will be particularly reactive, plus rising temperatures will create an “upside-down” snowpack. This means areas not affected by wind could avalanche as heavier snow sits on top of a lighter layer. Sensitivity will increase as the day goes on.

    Example photo: Natural and human triggered avalanches are likely on steep slopes, like this one in the Baker backcountry. Stick to low angle terrain away from steep slopes. 

  • Loose Wet

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

    Wet loose avalanches may begin early in the day where you find sufficient snow cover near the bottom of the mid elevation band. As temperatures increase, wet avalanche activity will reach higher, resulting in larger avalanches where more new snow exists. 

    Most wet avalanche activity will be limited to new snow that was previously dry. These avalanches could slide more easily on an underlying crust. If you notice snow getting moist and clumpy, or see any rollerballs or loose slides initiating, steer around these steep paths and lower angle terrain beneath them. 

    There's a tiny chance that lingering glide avalanches could still happen on steep, snow-covered cliffs where poorly-attached snow still remains. Avoid travel beneath areas where you notice these overhead hazards. 

    Example photo: Expect an uptick in wet loose avalanches as temperatures increase. They'll initiate easier from rocky outcroppings and tree bombs. 

Avalanche Discussion

Heather Meadows saw around four inches of rain from Sunday night to Monday, with other stations in the area reporting closer to three inches. A few inches of snow may have fallen at the top of the upper elevation band. Lighter precipitation with a freezing level around 3,000 feet is expected Monday night. On Tuesday, nearly an inch of water is forecast, with freezing levels rising to 5,000 feet in the afternoon. By day's end, mid-elevations could see up to a foot of snow, with one to two feet or more higher up. Winter is finally arriving in full force, so if you're heading out, be cautious of new snow hiding thinly buried hazards.

Several key access points are closed due to washouts and landslides. Recent storms have had a significant impact, both in the mountains and lowlands, making it difficult to reach many areas. Outside of weather station data, observations are limited, so be prepared to assess avalanche conditions yourself when entering snow-covered terrain. Snow totals and temperatures vary widely across the forecast zone.

With the warm start to the 25-26 winter season, we have less snowpack information than usual to start daily forecast operations. For zones and elevation bands with less snow than needed for avalanche hazard, we will issue a forecast with No Rating. Anticipated avalanche and weather conditions will still be updated daily. NWAC will issue an avalanche danger rating for a zone when enough snow to produce avalanches has accumulated at middle and upper elevations.

Régions couvertes