Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
1 · Low
Treeline
2 · Moderate
Below
2 · Moderate
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Incredibly slick frozen surfaces may be your greatest travel hazard on Thursday.  Consider your ability to arrest a fall before crossing any steeper slopes. If crusts do break down, you can trigger wet avalanches on steep slopes and they could grow to a large size.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    While surfaces will likely be frozen to start the day, we're in an unusually mild mid-December pattern and the crusts are not thick. If the sun comes out as forecast and breaks down the crusts, expect to sink into poorly consolidated snow where you can trigger an avalanche on open slopes steeper than 35 degrees. If you can sink into the snow to your boot packs, stick to lower angle terrain. Winds at upper elevations are unlikely to enable thicker crusts at these elevations to thaw.

    Wet loose avalanche activity on steep, sun-exposed lower elevation terrain.

    Photo: MHM Patrol

Avalanche Discussion

We're coming out of a noteworthy storm and avalanche cycle. Mt Hood picked up around 2" of liquid water at the tail end of a multi-day storm cycle that delivered 6-12" of snow each day for the 4 days prior to the rain event. 3 ft of dry snow sat above the 12/7 crust and this snow has now been saturated. We have reports of a widespread avalanche cycle that occurred Tuesday and Tuesday night: D1-2 size range, a size 2.5 and a size 3+ avalanche running a long way down Heather Canyon. You can see photos from some of this activity in the gallery. The avalanche danger decreased quickly as winds increased and formed "heinous and treaturous" travel conditions as strong winds created firm and breakable crusts!  Much of the snowpack structure that existed prior to the storm has been homogenized by the rain event.

On Thursday, despite the anticipated lower wind speeds, firm travel will be your primary hazard to start the day at all aspects and elevations. Make sure you bring appropriate sharps and have the skills to arrest a fall. Long sliding falls can impact experienced travelers.

As the day progresses, SE, S, and then SW aspects may soften. In more exposed areas they may stay firm throughout the day. Adjust your mindset quickly once you see the supportable surface crust replaced with a breakable crust, and then manky wet snow with the potential to entrain itself if destabilized.

If you head to the higher elevations on Mt Hood, you can find a patchwork of isolated recent or fresh shallow drifts overlying firm crusts in the Mt Hood zone. They should be easy to recognize by the change in texture or sheen of the snow deposits contrasting against the sheen of frozen surfaces. In some cases these shallow drifts may fill in crowns from Tuesday's widespread natural avalanche cycle.  You might find these deposits in the immediate lee of ridgelines or in gullies and they will probably only be hazardous on extreme terrain features. Identify and steer around areas where you expect deposits 6" or deeper that reside on slopes steeper than 35 degrees. Expect the danger to increase above around 8000 ft.

Keep in mind that the rain event likely exposed creeks and early season obstacles at lower elevations and near ridgelines that were previously covered. 

Regions covered