Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
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Danger d’avalanche

Mon
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The avalanche danger will rise Sunday afternoon as extreme winds form fresh wind slabs well below ridgelines.  Dangerous avalanche conditions will develop Sunday night as a winter-like storm impacts the Mt Hood area.  

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    With extreme westerly winds forecast Sunday afternoon, fresh wind slabs will likely form further downslope than usual and in unusual places due to chaotic loading patterns.  Shallow wind slabs may even form on open slopes below treeline before sunset. Steer around open slopes steeper than 35 degrees where you find freshly drifted and wind-stiffened snow.  Use small test slopes to gauge how the new snow is bonding to the old snow surface.  As snowfall becomes heavier Sunday evening,  the chances for human or natural triggered slab avalanches will increase further.   

    Example from Mt Hood earlier this month. Winter returns Sunday afternoon and night. Watch for shooting cracks in wind-stiffened snow. You may trigger a wind slab on nearby slopes.

Avalanche Discussion

Observers at Mt Hood Tuesday reported northerly winds and generally wind-packed snow surfaces near and above treeline that helped keep wet loose avalanches in check.  Older wind slabs were not reactive but there was evidence of large avalanches on lee slopes from earlier in the week.  Our attention turns to how the incoming snow will bond to the old snow surface.  In many cases, the moist or even wet snow surface will refreeze tomorrow as winds increase and the temperature drops late in the day.  Even by Mt Hood standards, tomorrow's storm looks to pack quite the wallop, with alpine winds averaging 60-70 mph by the afternoon.  This storm will continue well into Monday morning. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Régions couvertes