Bulletin d’avalanche

West Slopes Central

Northwest Avalanche Center
Voir sur la carte

Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
1 · Faible
Open full map
Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The 2022-2023 forecast season has started! Snow conditions may change quickly as you gain elevation and encounter more soft snow. Search for and avoid thicker wind-drifted deposits on steep slopes at higher elevations, as this is where you are most likely to trigger an avalanche. Danger may increase in the afternoon as winds increase and the next storm comes in.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–1.5

    It is possible that you could trigger an avalanche in wind drifted snow. Your likelihood of encountering thicker fresh drifts will increase as you gain elevation. The transition from minimal low-density new snow to a much thicker coating may happen quickly, so be sure to pay attention to the snow beneath you as you gain elevation. Search for signs of instabilities like long, shooting cracks or whumphing as indicators to avoid steep slopes. Wind will increase in the afternoon, and the next storm will begin picking up at the end of the day. Pay attention as these changes occur, as danger may increase as new or larger drifts form. 

    Shooting cracks like this one coming from skis, snowshoes, feet, etc are indicators that a reactive wind slab exists.

    Photo: Lee Lazzara

Avalanche Discussion

Leading up to this week, 2-3 feet of snow was on the ground at mid to upper elevations. This snow sat under high pressure from Nov 8 - Nov 21. Weak, faceted crystals formed in shady areas. Meanwhile, hard, sun-affected surfaces developed on south-facing slopes. Upper elevation treeless terrain was buffeted with wind from all directions, so fewer pockets of weak snow developed on shady aspects here.  

Almost 2 inches of rain fell Nov 22, destroying most of our weak snow concerns. Many surfaces are now capped with a crust from that rain event, although above approximately 5000ft enough rain may not have fallen to destroy any weak layer which managed to persist despite the wind. In a few isolated areas, there may be pockets of weak snow beneath newer layers. You are probably more likely to find this when you get closer to the divide. Information is limited at this time. Please share with us information about your travels if you get out on Saturday by submitting an observation. 

Snow cover is thin this time of year, especially in near and below treeline areas. Travel carefully to avoid hitting stumps or rocks, or falling in an open creek. Snow conditions are extremely variable depending on elevation. We’ll be seeing more snow coming in Saturday night and in the meantime, have a great start to the winter!

Régions couvertes