Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

An erratic distribution of slabs at upper elevations on Mt Hood serves as a reminder of recent strong winds. These slabs will be joined by a new crop as increasing SE winds and snowfall late in the day build hazards on atypical aspects. Pay particular attention to active transport to identify the more reactive, fresher slabs later in the afternoon.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    SSW through WSW winds were ripping on Mt Hood through early Saturday, transporting 3-7" of recent colder snow at upper elevations. This snow has been beaten down into a patchwork of shallow dense, erratic slabs. Most of these slabs losing reactivity. But in areas with punchy layering within the recent snow above the old snow interface, you can still trigger one on colder, shaded aspects.

    As SE winds develop, a new crop of wind slabs will grow on atypical aspects (generally the W side of the compass). This process will accelerate as new snowfall arrives in the afternoon. Re-focus your attention on these fresher slabs forming on atypical aspects as these shallow slabs may be easy to trigger. 

    Regardless of whether you're dealing with new or older slabs, identify areas where active or recent wind loading has occurred and don't use your typical assumptions about where slabs generally form. Use test slopes to gauge reactivity as you move into more hazardous terrain with elevation. If the snow arrives earlier than expected, slab hazard will increase more rapidly and could elevate the danger at middle elevations as well.

    Example:  A patchwork of wind textured snow overlying a firm, older crust. It is within these drifts that you can trigger a slab on the crust.

    Photo: Mt Hood Climbing Rangers

Avalanche Discussion

SE winds will ramp up ahead of the next system and will transport limited remaining available snow from shaded aspects onto the W and N sides of the compass. The timing of the incoming precipitation will determine whether conditions stay generally safe at middle elevations, but we're expecting up to 2" of snowfall in the 2-5 PM time frame.

A solid overnight refreeze Friday night put our deeper wet slab concerns to bed. We're expecting another solid refreeze Saturday night. At the lowest elevations (below 4000 ft), there still could be some areas that haven't seen a good refreeze. Be cautious around and beneath blocks of snow which could still release in rocky areas.

Mild temperatures in the mid-morning hours could destabilize any less wind-affected snow as filtered sunshine preferentially impacts E and SE aspects at that time of day, increasing the risk for shallow wet loose avalanches that you could push into existence or might see naturally release. These should be less than a D1, for the most part.

If you get out into the mountains, let us know what you see by submitting a public observation here. 

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