Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Tue
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Forecast updated 7:30 AM to high avalanche danger near and above treeline.

Very dangerous conditions have developed. Snow measured in feet, combined with warming temperatures provides a recipe for widespread natural and human-triggered avalanches on Monday. Avoid all avalanche terrain including any open slopes steeper than 35 degrees where avalanches can start, stop, or run.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–2.5

    36 hours of heavy snowfall on Mt. Hood has created dangerous storm slabs you can trigger at elevations. Warming temperatures will exacerbate the problem as the day wears on. A 0.25-0.5" crust layer from 12/18 will be worth assessing as it makes for an efficient interface for the 2-3 ft (very large) storm slabs to run on. Mid-storm layers could also develop. Avoid all avalanche terrain including anywhere avalanches can start, stop, or run.

    (12/18/2021)

    Example: A small natural storm slab. Storm slabs on Monday may be much larger than the one in this photo. Highway 542 near Mt. Baker Ski area.

    Photo: NWAC Public Obs

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2

    The rain/snow line will be highly uncertain on Monday. With all the new snow, any transition to rain will produce large avalanches that can entrain down to the freezing rain crust. These avalanches will be powerful, may be human or naturally triggered, and difficult to manage. Avoid all open slopes steeper than 35 degrees.

Avalanche Discussion

Forecast updated 7:30 AM.

We're in the midst of a multi-day storm at Mt. Hood. As of Monday morning, most areas on the mountain picked up 20+ in of snow in the last 24 hours with over 2" of snow water equivalent, creating a heavy, dense slab and very dangerous avalanche conditions. Adapt your plans given and stick to low-angle slopes and densely treed terrain.

Sunday morning, MHM Pro Patrol triggered 4-10" slabs in near treeline terrain and 2-6" slabs lower on the mountain that ran on the 12/18 rain crust.  Additional low-density snow has yet to consolidate. However, we expect that an additional 1-1.5" inches of snow water equivalent, combined with some warming Tuesday afternoon will be sufficient to turn the low-density snow into a cohesive slab you can trigger. Further dial back your terrain selection and recognize that as the slabs increase in size, your risk increases markedly.

Our focus remains above the 12/18 crust and we don't currently have any layers of concern deeper in the snowpack.

While the new snow has been filling in the terrain, early-season obstacles do exist in some areas. Creeks are definitely still open and present travel challenges.

Regions covered