Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
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Danger d’avalanche

Mon
Alpin
4 · Fort
Limite forestière
3 · Marqué
Sous la limite
3 · Marqué
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Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Heavy snowfall and extreme winds will create very dangerous avalanche conditions at upper elevations over the next 24 hours. Large natural avalanches could break over 2ft thick and run far distances. Travel in or below avalanche terrain is not recommended.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–2.5

    A potent storm looks to bring 10-18in of new snow above 4500ft by Sunday afternoon and 30-50mph SW winds at upper elevations. The most dangerous conditions will develop in wind-loaded alpine terrain where a natural avalanche cycle is expected. Avalanches could grow large, breaking on the new/old snow interface or within layers of new and wind-drifted snow.  You could easily trigger avalanches on slopes 35 degrees and steeper in all elevation bands, even in non-wind loaded areas. Give the snowpack time to adjust to the heavy load of new snow. Choose simple, low-angle terrain away from the run-out of large avalanche paths.

    Example photo of an avalanche in new and wind-loaded snow. We expect similar avalanches Sunday.

    Photo: Mt Hood Meadows Patrol

Avalanche Discussion

Big changes in the weather will cause big changes in the snowpack, and avalanche danger will spike from LOW to HIGH overnight Saturday. The storm will begin warm and wet Saturday night before snow levels drop to 3500ft on Sunday. The heaviest precipitation rates are expected Sunday morning and wind speeds will increase throughout the day. Blizzard conditions with low visibility and deep snow will make for challenging travel. Only venture out in the storm if you are confident in your ability to identify and avoid avalanche terrain. 

Saturday brought a stark transition from sunshine and warm temperatures to ominous clouds and increasing winds. The most recent avalanches occurred 4 days ago, and observers on Saturday reported generally stable conditions. The mid and lower snowpack is consolidated and strong, and avalanche activity moving forward should occur at or above the new/old snow interface. The warm start to the storm may promote a favorable bond to variable old snow surfaces. Regardless, the new snow will need time to settle and stabilize.

Observations from Illumination Saddle on Thursday showed a variety of hazards on the upper mountain and several avalanches from the last storm. Most of these avalanches occurred on 3/8 and were primarily small loose dry sluffs. A handful of shallow wind slabs also ran during this time, and an impressive glide-like avalanche released from the Hot Rocks above the Zigzag Glacier. Also noteworthy was a large crevasse opening on the White River Glacier.

Régions couvertes