Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

We may only get a short-lived superficial refreeze overnight before temperatures rise again in the afternoon. You may still trigger a wet avalanche on steep slopes. The potential exists for a smaller wet avalanche to step down to deeper weak layers and trigger large slabs on higher elevation, shaded terrain.

Avalanche problems

  • Loose Wet

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

    The recent snow is still hasn't fully transitioned into a spring melt-freeze cycle. Wet loose avalanches are likely a more significant problem in higher elevation terrain near the Cascade crest that received more snow recently. Signs of wet loose avalanche activity are rollerballs, fresh fan-shaped avalanches with chunky-looking debris, and sometimes you can hear them. Steer around large steep features if you can sink in deeply into wet snow.Natural wet loose avalanches are unlikely, but you could trigger them on steep slopes. Use caution in consequential terrain where even small avalanches can bury you in deep ravines, push you off cliffs, or into trees or rocks. Although wet avalanches would be less likely on higher elevation northerly aspects if one occurred, it could pull out wider slab avalanches on deeper layers. Above 5,500ft, NW-NE aspects harbor weaker, faceted grains over a crust from early March. This layer could be down close to 3ft deep in some areas, and an avalanche that runs on it could be large. There is uncertainty about how the snowpack is adjusting, so keep an eye and ear out for signs of current activity.

    (1/24/2022)

    Example of small loose wet slides. Big Slide Creek in upper Icicle Creek drainage.

    Photo: Matt Primomo

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    With continued warm temperatures and only a superficial refreeze overnight, you can still trigger a persistent slab in northern aspects at upper elevations. Observers have reported some whumphing collapses, and a skier triggered an avalanche 2ft deep last weekend. These are all direct signs of instability relating to a layer of faceted grains overlying a crust buried in early March. However, many observers reported a lack of whumphing collapses but still found a weak structure in profiles. This insight is unsettling because it is difficult to discern which slopes may avalanche. Therefore, it is best to approach all steep northerly aspects at upper elevations with suspicion. Any avalanche that runs on the crust could be a couple of feet deep and fairly wide. Plan to stay off large and steep, shaded slopes above 5,500ft, especially if they appear to have been loaded by the wind in recent days or if the snow is wet and punchy. Instead, travel on lower angled slopes without large steep features above you. Large loads like cornice failures or snowmobiles could initiate persistent slabs more easily.

    Example recent slab avalanche from the East South zone.

    Photo: Andrew Kiefer

Avalanche Discussion

After a brief overnight freeze, expect temperatures to climb back into the mid 30's on Thursday. I observed 4-6" of recent snow over a crust on Dirtyface on Tuesday, with snow that was not yet fully transitioned to spring-like corn snow. Higher elevation locations near the crest likely received closer to a foot of new snow since the 20th. Large wet loose avalanches were observed at high elevations of the Chiwaukums, Stevens Pass, Snoqualmie Pass and the warming likely affected snow surfaces even on the highest, shadiest faces of the range. 

Observers have been documenting weaker, faceted grains and/or surface hoar overlying a crust from early March on W-N-E aspects from Stemilt Basin to Icicle Creek, and other areas to the north and south. Above 5,500ft, these slopes harbor weaker, faceted grains over a crust from early March. This layer could be down 2ft deep or greater in some areas. On Sunday, skiers triggered an avalanche on it near Mt Fernow that was 2ft deep and 40ft wide. Observers in the Chiwaukum range also found the weak layer above 5,000ft and reported significant wind loading on Saturday. On Friday, I found the March 8th facets in the White Pine drainage. A vague observation of large collapses in the Teanaway also came in from Saturday (unknown details). 

Regions covered