Avalanche forecast

East Slopes North

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Avalanche danger is on the rise, with a substantial uptick in wind speeds and another couple inches of snow. Slabs should be fresh and reactive, as they'll form during the day. Look for signs of instability like shooting cracks or whumphing collapses, and be ready to navigate around steeper features.

Avalanche problems

  • Wind Slabs

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

    Increasing winds will drift the recent snow into more cohesive slabs on exposed mid and upper elevation slopes. These could be surprisingly reactive, as they may form over weaker snow on a crust. These could be 6"-18" deep in favored locations. Use caution to evaluate steeper slopes, especially if you observe active wind loading, shooting cracks or hear whumphing collapses. Likely spots to find these wind slabs are below sharp ridgelines, at the top of confined gullies, or the base of cliffs. Textured surfaces, deeper drifts, and cornice formations can also help you identify likely wind slab locations. 

    Small loose dry sluffs could also be possible in some areas. If you find the snow is prone to sluffing, or cracking, than consider routing around more consequential areas.

    (12/13/2023)

    Example small wind slab on Blue Lake Peak from mid December.

    Photo: Matt Primomo

Avalanche Discussion

Winds have already been gusting to 23 mph as I write, and should continue to increase on Friday as a stronger storm approaches.

An observer on Thursday found 3" of new snow near Blue Lake. Hereported light drifting snow during the day, while winds were just beginning to increase. Earlier in the week, observers in the Kangaroo ridge area reported firm, wind affected surfaces at very high elevations with minor cracking. They also reported a slightly older and unique glide avalanche (see photo below). It may have occured during warm temperatures on Dec 29th-30th. Observers have found soft, dry snow on sheltered, northerly slopes, with firmer surfaces in sun and wind-exposed terrain. 

Further west of Washington Pass near Kitling Peak, an observer on 1/1 and 1/2 reported a much more shallow snowpack. He found 3ft at 6,500ft, with less snow overall on top of the thick melt freeze crust from earlier in December. One of the drainages near Swamp Creek had sent rock and mud debris down Hwy 20 for at least a mile westbound. This likely occurred with the atmospheric river in early December. 

Observers have reported weak layer/crust combinations in the top foot of the snowpack near Washington Pass and Harts Pass. They've found little potential to trigger avalanches where the crusts are thick and the overlying snow is decently bonded, but there's uncertainty for areas where the crusts could be thinner and weak layers could be more pronounced. For an idea of what you might find in the southern portion of this zone, like mid-Twisp River drainage, check out these observations from the Holden area.

You can help out by contributing to the forecast. Submit an observation, and let us know what you see! 

Regions covered