Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Avalanches in wind drifted snow will continue to be easy to trigger on Friday. So avoid steep slopes with pillow-like drifts and confined alpine terrain features. We expect these slabs to be larger, more widespread, and easier to trigger as you ascend in elevation. 

Avalanche problems

  • Wind Slabs

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

    Many reports of skier-triggered wind slabs came in on Thursday. You can anticipate little change in these sensitive wind slabs with cold temperatures and continued easterly winds. This easterly wind direction can surprise backcountry travelers used to focusing on slopes or aspects that are more commonly wind loaded by the typically westerly winds. Steep slopes below ridges and confined alpine terrain features such as chutes and gullies are likely places to trigger these wind slabs. It may be challenging to avoid these wind slabs at elevations above treeline, and you can also expect to find them on open slopes at lower elevations. Ease into the terrain using smaller, less consequential slopes to see how the snow reacts. If you find cracks or feel firm hollow snow underneath you, step back and stay off these suspected wind-loaded areas.In wind-sheltered areas, it's still possible that you could trigger a storm slab avalanche on steep unsupported rollovers. As the sun comes out and temperatures moderate, you may still see some small dry loose avalanches running in very steep terrain. Don't let a smaller avalanche knock you over and take you for a ride above a terrain trap. 

    (1/9/2022)

    Example from last season of East Winds transporting snow onto the opposite side of the ridgeline (and opposite recent cornice growth) from where we typically see Wind Slabs forming.

    Photo: Andy Harrington

Avalanche Discussion

Avalanche Fatality: Colchuck Pk, East Central Zone: Read the preliminary report here.

It was an active day on Thursday, with multiple reports of human-triggered avalanches. Most of these avalanches were on wind loaded test slopes and intentionally triggered. However, a skier was caught and carried a short distance by a small avalanche in a confined terrain feature, and they were on the surface and uninjured. Read more in the Observation. A large natural storm slab occurred on Chair Peak, and we suspect a cornice fall may have been the trigger. We do not think that this avalanche involved older snow layers. While we expect this avalanche to be the exception rather than the norm, we can't rule out larger storm slab avalanches with the amount of recent snow that has fallen. So slowly approach new terrain and assess conditions before committing to challenging terrain. 

The recent snow is generally right side-up with up to 2' of snow above the heavier, wetter snow received earlier in the storm cycle. With several inches of fluffy, low density snow to end the storm, several natural dry loose avalanches were observed in steeper terrain. Current observations of recent avalanche activity involve just the recent snow above the rain crust/refreezing wet snow. We are still monitoring deeper interfaces in the snowpack, such as the 2/17 or 2/13 melt-freeze crusts. While we don't suspect these layers to be active, there is still an unlikely possibility of avalanches on these layers. This would most likely occur in isolated areas with a larger trigger, like a cornice or a smaller avalanche that steps down deeper in the snowpack.

Regions covered