Bulletin d’avalanche

East Slopes North

Northwest Avalanche Center
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Danger d’avalanche

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

Points saillants

We have limited information about the snowpack in the East North zone.  After a week of well below normal temperatures and light occasional snowfall,  you may encounter shallow wind slabs on a variety of aspects below ridgelines or small loose avalanches in very steep terrain.

Problèmes avalancheux

  • Wind Slabs

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

    Unusual Easterly winds Monday through Wednesday night moved snow along ridgelines and potentially on open slopes below treeline during our extended April cold spell.  E-SE winds will pick up once again Friday night and Saturday morning before switching to Westerly Saturday afternoon. 

    Observers in neighboring zones have been ecstatic about the late season low density snow, it's certainly been an April to remember conditions-wise.  You may still trigger a shallow wind slab at upper elevations on Saturday.  The extended period of Easterly winds earlier in the week may have formed wind slabs on unusual aspects compared to our usual storms from the South or West. 

    Use caution or steer around steep slopes where winds have recently drifted snow.  Shooting cracks or recent avalanches are red flags to stay off similar slopes.  Fresh cornices may have formed in unusual places along ridgelines given the recent pattern.  Tread carefully along corniced ridgelines, giving them a wide berth.

    Loose avalanches, wet or dry, are a concern in very steep or extreme terrain.  If the sun comes out for an extended period, wet loose avalanches may shed from below cliff bands or slopes steeper than 40 degrees.  On slopes holding cold loose snow, take care near terrain traps where a small sluff could knock you off your feet and do damage. 

    (4/13/2022)

    Textured snow surfaces have been easy to find throughout the Cascades this week with fresh snow and periods of strong E winds.

    Photo: Craig Muderlak

Avalanche Discussion

What a week it's been for winter conditions in the Pacific Northwest.  Earlier in the week, Washington Pass picked up 10-12" of gradually settling snow above the 4/8 crust with 4-6" at Harts Pass  4-6".  Strong Easterly winds were recorded at Washington Pass and throughout the Cascades with Monday's storm.  Light to moderate easterly winds and lighter showers continued through Wednesday night.  Afternoon and evening showers have likely added another inch or two of snow both Thursday and Friday.  Washington Pass saw an impressively large diurnal temperature swing on Friday, with a bone chilling low of 3F at Pass level, rising to 33F in the afternoon.  

Information and observations are limited. Access to snow-covered slopes has become difficult in many parts of the zone. Be prepared to make your own observations and assessments. If you see conditions different from what we describe, defer to lower-angle and simpler terrain. The North Cascades Highway SR 20 is currently gated at Silverstar, though the road is plowed further west. Until the road opens,  WSDOT allows recreational access on the North Cascades Highway near Washington Pass from Friday-Sunday. With road clearing operations underway midweek and other professional operations inactive, your observations are needed. If you're out in the mountains, let us know what you see. 

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