Bulletin d’avalanche

East Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Sun
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 6 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

You may be able to trigger shallow avalanches on slopes steeper than 35 degrees, especially where you find recently drifted snow at upper elevations. In the eastern mountains, you may be able to trigger avalanches in older weak layers. Expect light snow accumulations with southerly winds increasing by afternoon.

Problèmes avalancheux

  • Loose Dry

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

    It may be easy to trigger shallow, loose avalanches on slopes steeper than 35 degrees where the old snow surfaces are slick or firm. They could run far and fast. While these avalanches can be easier to predict, they can still be dangerous. Use caution around terrain traps. Fast running avalanches could push you off of cliffs or into rocks. In gullies, a shallow avalanche could add up to deep debris piles.  Make sure not to travel above other people and expose only one person at a time to avalanche terrain. Observers have reported loose avalanches running in the snow that has fallen since the 24th.

     

    (1/27/2021) Loose dry avalanches have been occurring over slick crusts in the area. Photo by Drew Lovell.

  • Wind Slabs

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

    You may still be able to trigger avalanches in slabs that were drifted by wind on the 26th and 27th. There may also be isolated fresh drifts forming from southerly wind throughout Saturday and into Sunday. Look for these immediately on the leeward sides of ridges and upper elevation terrain features.  Watch for plumes of blowing snow at ridge tops. If you see cracks or of deeper pockets of snow, move to lower angled parts of the slope. Avoid wind-loaded convex rolls and unsupported features where you may be able to trigger avalanches more easily.

Avalanche Discussion

Light snowfall has slowly loaded a variety of snow surfaces since January 24th. At upper elevations near and just east of Washington Pass, the snowpack is deep and strong, though faceted snow was observed on shaded aspects prior to the storm. Below about 5,000ft in the Highway 20 corridor, large surface hoar was observed sitting on a crust prior to the recent snow. On Wednesday, observers in the eastern mountains of the lower Methow Valley reported cracking and collapsing on older facets in snow from early January. Expect to find a shallower and weaker snowpack in the eastern part of the zone. If you travel to areas such as the Chelan-Sawtooth Mountains, Twisp River, and Chewuch drainages, take time to dig in the snow and look for older weak layers and consider traveling in lower angle terrain and smaller terrain features.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources. Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Régions couvertes