Bollettino valanghe

East Slopes North

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 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

You may be able to trigger small avalanches in wind-drifted snow at upper elevations. Watch for falling cornices as temperatures warm. Don't linger under cornices and reduce your uncertainty by steering around drifted pillows of snow on steep slopes. 

Problemi valanghivi

  • Wind Slabs

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

    Avoid nearby steep slopes if you see long, shooting cracks in firmer wind-textured snow or signs of recent avalanches. Slopes beneath large cliffs also tend to harbor slabs, as loose snow spindrifts off and accumulates below. You can always pivot to well-supported and lower-angle slopes or seek wind-sheltered terrain for travel. In the past week, observations reported stiffer wind slabs and long shooting cracks at upper elevations. While older wind slabs should be more difficult to trigger, a weak faceted snow layer underneath has allowed this problem to linger. There's been a variety of wind directions drifting snow. Consider the consequences of triggering a wind slab that breaks wider and deeper than expected if it fails on weak snow above a stout crust from January 31st. 

    A wind slab avalanche ran on the 1/31 crust last week (2/9). Copper Creek, SE, 7200ft

    Photo: Harry Keane

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2

    Cornices typically fall as temperatures warm. They're a hazard in their own right, but cornice failures can also trigger avalanches on slopes below. Avoid lingering underneath these behemoths. Be aware of any overhead cornice hazard, especially if poor visibility prevents you from seeing terrain above you. When traveling on ridges, keep plenty of distance from the edge and be sure that you're traveling on the part of the mountain and not on overhung snow.

    (1/25/2024)

    A natural avalanche (D1.5) was initiated by cornice fall during a warm-up in January. Poster/Pika Pk NE, 7,2000ft

    Photo: North Cascades Mountain Guides

Avalanche Discussion

Wednesday will again feature a common pattern of cloudy skies with light snow or rain at low elevations. Similar to Tuesday, expect warmer temperatures and a chance for rollerballs or small, wet avalanches below 4000ft. 

Observers have generally reported small skier-triggered and natural wind slab avalanches over the past week, primarily from upper elevations. Sunny weather on Friday formed a thin sun crust on southerly aspects at mid and lower elevations. On shady slopes, at mid and upper elevations, there is up to 1.5ft of recent snow over a stout crust from January 31st. Lower elevations hold substantially less new snow over this crust, so travel may be challenging and slippery in some areas. A layer of faceted snow rests above the crust from January 31st, and may be the culprit for the prolonged instability in wind-affected terrain. 

Snowpack information is limited outside of the Highway 20 corridor and Harts Pass. Let us know what you find if you get out into the backcountry!

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