Bulletin d’avalanche

East Slopes North

Northwest Avalanche Center
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Danger d’avalanche

Fri
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

Expect cold temperatures, sun, and light winds. Watch for triggering small, loose avalanches on steep slopes. Although it's unlikely, the consequences of an avalanche in deeper weak layers of snow could be serious.

Problèmes avalancheux

  • Loose Dry

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

    Near the Cascade crest, you may be able to trigger loose dry avalanches in the recent snow on steep slopes, especially near and above treeline. Watch for triggering these predictable avalanches at your feet or machine, especially on convex roll-overs or slopes 40 degrees or steeper. Loose avalanches can be dangerous if they push you into terrain traps such as trees, rocks, or gullies. When traveling on slopes, be sure no one else is below you. Snow surfaces are still light and soft after a storm over the weekend. Cold temperatures may continue to weaken the surface snow. 

    (2/21/2022)

    Loose avalanches on a steep slope in the Stevens Pass zone. 

    Photo: Public obs

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    2

    Persistent slab avalanches have become difficult to trigger. On the off chance that you trigger one, the consequences could be serious. You can still find the weak layer in snowpack tests on shaded slopes near and above treeline. When in doubt, consider steering clear of shallow, rocky, or unsupported steep slopes.

    Indicators of persistent slabs are whumphing collapses and snowpack tests that pop or drop suddenly. While it's been 2 weeks since the last reported persistent slab avalanche, observers reported these signs of instability more recently. You can dig and find the late-January weak layer about 2 feet below the surface. This layer is a combination of weak sugar-like facets sandwiched between two crusts in many areas. Sometimes you'll find weaker snow above the crust. The weak layers are deepest near and west of the Cascade crest and in wind deposited areas. 

    (2/5/2022)

    A skier triggered avalanche near Maple Pass. Three people were caught, one was carried over 400ft with no injuries. E, 6,600ft

    Photo: NWAC public obs

Avalanche Discussion

While temperatures will ease a bit on Thursday, it will still be cold. After a dusting of snow overnight, sunny skies will return during the day. Looking ahead, the weekend may hold unsettled weather.

Most recently, winds may have been strong enough to transport snow at the highest elevations since Tuesday. A storm over the weekend brought about 10-14 inches of snow with westerly winds near Washington Pass. Some older wind drifted slabs may be lingering on leeward slopes at upper elevations, but wind slab avalanches are generally difficult to trigger. 

Régions couvertes