Avalanche forecast

Mt Hood

Northwest Avalanche Center
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Avalanche danger

Wed
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

If surface crusts break down, you can trigger a generally small wet avalanche as the snow becomes moist. You might find the key ingredients on steep, sheltered, south-facing slopes harboring softer snow. Adjust your aspect and reduce your exposure to long, steep slopes where wet avalanches might initiate around warming rocks or cliffs.

Avalanche problems

  • Loose Wet

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

    Tuesday will be even warmer than Monday, with freezing levels rising above the top of Mt Hood. We're expecting only very thin high clouds. Steep south-facing slopes surface crusts that may weaken or break down on Tuesday. Steep, sun-exposed slopes are where you are most likely to find destabilizing surface snow. These slopes proved minimally reactive on Monday, so it would require significantly more sunshine to expect an increase in activity. Slope angle plays a major role this time of year, so pay attention to steeper slopes near or above you as wet loose activity can initiate naturally. While most will be small, they could grow a bit larger, running the length of a longer, steep slope. You can trigger these if you find slushy snow up to your ankles. Give the snow a push on a steep, south-facing snow and see whether it entrains or stops. In the case of the former, shift to lower-angle slopes or move away from sun-exposed aspects.

    Example: Wet loose avalanche on a south face that received direct solar heating.

    Photo: Koby Yudkin

Avalanche Discussion

We're in the midst of a warm, late-December high pressure ridge on Mt Hood. Prepare for cool temperatures to start the day at lower elevation trailheads, but spring-like warmth at mid and upper elevations.

Observers reported light NW winds and some moistening of steep S-facing middle and upper-eleveation slopes on Monday, but little in the way of instability. The south-side of Mt Hood has healed nicely from snow and strong winds that produced reactive slabs and triggered avalanche activity on 12/26 and 12/27 (see gallery). We have a bit more uncertainty about the state of old wind slabs at higher elevations on shaded north-facing slopes, so keep this on your mind if you head onto extreme terrain features and unsupported slopes in farther afield data-sparse areas like the north side of Mt Hood. 3-day-old thick wind slabs are typically trending unreactive to humans, but a sun-drenched cornice fall might wake them up.

The last storm brought 10-12 inches of new snow since Christmas Eve. Below 7000 ft, this new snow rests over a thin melt freeze crust that formed during the brief warm-up on Christmas Eve. Some recent avalanche activity matched these depths, but a weak layer was never confirmed in any of them. Snowpack tests have shown some weaker snow around this 12/24 crust, but we haven’t seen this weak layer fully propagate in longer columns yet and it should be gradually gaining strength. This layer will likely provide less feedback during the current stagnant weather, but it may be worth digging deeper to assess the bond before riding steep, open slopes.

Despite recent accumulations, the snowpack remains thin by late December standards and snow depths increase markedly above 6,000 ft. Keep an eye out for shallow coverage down low, scoured west-facing aspects, or thinly bridged crevasses in alpine terrain. 

 

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