Bollettino valanghe

East Slopes Central

Northwest Avalanche Center
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Pericolo valanghe

Thu
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Use caution when approaching slopes where you expect to find firmer wind drifted snow.  It's here you may trigger an avalanche from lower angled terrain or one that breaks widely over terrain features. Warning signs include whumpfing collapses, drifts of freshly blown snow, and a layer of weak, sugar-like snow over a crust roughly 12-18" below the surface. 

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Persistent slab avalanches are dangerous and can catch even the most experienced backcountry travelers by surprise. We also know that fresh wind slabs formed on open slopes near and above treeline Tuesday and that you're likely to find deeper slabs below ridgelines in areas closer to the Cascade crest.  As you start to transition both in elevation and aspect, look for evidence of firmer wind transported snow, avoiding terrain steeper than 30 degrees in these areas.  Give yourself an extra buffer while traveling along ridgelines and in terrain connected to steep open slopes above.  

    Observers have reported a layer of weak snow (facets 1.0-1.5mm) resting on a crust that formed in the past week. Near the Cascade Crest, you can find this weak layer about 10-20 inches (25-50cm) below the surface. On Monday, observers in the Highway 2 corridor near Lost Lake, as well as close to Stevens Pass, reported collapses up to 100ft in diameter and snowpack tests that indicated propagation.

    Sticking to treed terrain, lower angle slopes without overhead exposure or windward aspects will help you travel safely on Wednesday. 

    (12/14/2020) Observers found up to 8 inches of snow over a facet crust combo near Lost Lake. They reported whumphs as big as 100ft across on this weak layer.

Avalanche Discussion

Wednesday will offer a brief reprieve from our active weather pattern.  The avalanche danger will quickly rise Wednesday night as a stronger storm impacts the area. 

On Tuesday, the avalanche danger will be the greatest on the west side of the zone. In the Wenatchee Mountains near Blewett Pass and the eastern foothills of the Cascades, you may find less dangerous conditions along with less snow.  Expect shallow snow cover at low elevations and bare ground particularly on low south-facing slopes. Typical early season hazards can be expected with open creeks, stumps and rocks. 

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.

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