Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Wed
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

You can trigger avalanches in wind drifted snow at upper elevations, especially in areas closer to the Cascade Crest. Use visual clues to identify and avoid wind-loaded slopes greater than 35 degrees. Shallow snow cover will continue to create challenging travel and increase the consequences of any avalanche.

Problemi valanghivi

  • Wind Slabs

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

    Expect strong westerly winds and light snowfall to continue on Tuesday, creating fresh drifts and thickening existing slabs. Avalanches will become larger and more sensitive to triggers as you climb up in elevation, especially in areas further west in the zone that have a deeper snowpack Pay attention as you transition into wind-affected terrain and use caution around ridgelines, rollovers, and steep rocky features. Evaluate snow and terrain carefully and look and feel for signs of wind-loading like cornices and changes in snow surface texture and hardness. In wind-sheltered areas, you may find unconsolidated snow with loose dry sluffs possible in steep, unsupported terrain.

    (12/9/2021)

    Example:  Shooting crack in wind drifted snow in Sand Canyon on Mt Hood (E aspect, 6200ft).

    Photo: Andrew Kiefer

Avalanche Discussion

Over the weekend, there were several reports of human-triggered avalanches throughout the Cascades, including an accident in the adjacent West South Zone that resulted in one fatality. (See preliminary report below)

Since 12/8, 1-3ft of new snow fell throughout the East South Zone. We have minimal observations and a lot of uncertainty about snowpack conditions near and above treeline. In areas near the Cascade Crest, a layered winter snowpack is developing. Far to the east and at low elevations, snow cover is shallow, and below the threshold to produce avalanches. Use your probe to investigate snowpack depths as you move through the terrain and hand pits or small test slopes to help identify how well recent snow is bonding to the underlying surface. Keep in mind there is a lot of variability this time of year, and what you find on one slope may be very different from the next. 

Preliminary Report: On Saturday morning, December 11, a party of six backcountry tourers were traveling uphill in a closed section of the Crystal Mountain Ski Area known as Silver Basin. The party triggered a large avalanche on an NE to E facing slope at approximately 6600’. While all members of the party were initially caught, four were fully buried. A nearby party of two witnessed the event and immediately assisted in the rescue. Crystal Mountain Ski Patrol was also notified and responded to the scene. Unfortunately, one of the fully buried victims did not survive. NWAC and Crystal Mountain Ski Patrol will collaborate to conduct an investigation. Our deepest condolences to the family, friends, and community.  SS-ASu-R3-D2.5-U; Crown Depth: estimated 2’ deep.

While we're excited about issuing daily forecasts for the East South zone this season, we need your help in making this successful. However and whenever you recreate in the mountains this winter, please send us your observations.  - The team at NWAC 

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