Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
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Danger d’avalanche

Thu
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

You can find wind-affected snow throughout the upper elevation slopes of Mt. Hood. Steer around areas of active wind loading, extreme terrain features, or poorly supported slopes where you can still trigger an avalanche. At lower elevations, Wednesday will be a good day to observe the distribution of weak surface snow before the next storm.

Problèmes avalancheux

  • Wind Slabs

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

    Recent winds shifting from WSW to NW have battered the snow surfaces throughout the exposed terrain on Mt. Hood, creating wind ripples, exposed ridgelines, and pockets of wind slab that may be reactive to human trigger. Since wind-affected snow exists thoughout the terrain, focus on your terrain selection. Slopes approaching 40 degrees or steeper and those that roll away out of sight below you are the ones to avoid. Fresh snow transport will also guide you toward more isolated areas of building hazard. You can trigger these slabs anywhere drifts form 6" or deeper. 

    On Monday, several observations came in from the Hogsback on the upper slopes of Mt. Hood where folks were taking advantage of the excellent weather. A human triggered avalanche and the identification of wind slabs over weaker snow layers serve as a reminder careful snowpack evaluation is necessary at these elevations where NWAC forecast ratings don't apply. Slabs on the upper mountain tend to be larger and more widespread with snowpacks that we can't assess on a regular basis.

    (12/6/2022)

    Active snow transport onto slopes increases your risk of triggering an avalanche on a steep or unsupported slope below.

    Photo: Joe Dellaporta

Avalanche Discussion

NWAC forecaster Joe Dellaporta was on Vista Ridge on Tuesday. A test pit at 5700 ft on an E aspect was 65 inches deep and indicated no layers of concern with right-side-up snow well bonded to the thick11/22 crust.  Shaded areas in the trees are growing surface hoar and near surface facets. He found active snow transport along ridgelines with heavily scalloped snow along the tops and walls of canyons. Wind slabs were gradually losing reactivity to human trigger. On Monday, Mt. Hood Meadows was able to trigger small wind slabs with explosives, but most slabs were hard for skiers to trigger.

If you get out this week, please submit an observation on our public observation platform!  These observations play an integral role in producing a quality avalanche forecast, but also help the greater backcountry community.

Régions couvertes