Avalanche forecast

West Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 6 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Avalanche hazard likely only exists in locations where more than 4-6 inches of recent snow accumulated over the old crusty surface. This is most likely higher in the terrain. Be leery of steep slopes in these areas, especially as the sun causes the snow to become wet and mushy.

Avalanche problems

  • Loose Wet

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

    The recent snow will see the sun for the first time on Tuesday. This often results in snow falling off rocks and trees. If you start to feel the warmth of the sun, odds are, so is the snowpack. You may notice or trigger fresh rollerballs as a precursor to wet loose avalanche activity. As things warm up, have a plan to head to shadier or lower angled terrain in order to manage this problem. 

    This issue takes two forms. You may trigger your own avalanche on steep southerly slopes. This is often easy to anticipate and, since these slides should be small, might even be manageable. These avalanches are most problematic in higher consequence terrain where they can push you over a cliff or flush you down a narrow chute. Natural avalanches might also occur from cliffs and rocks. Fortunately, these slides should be isolated to craggy faces basking in the sunshine.

    Example: Natural wet loose slide releasing from rocky terrain basking in the sunshine. 

    Photo: Lee Lazzara

  • Wind Slabs

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

    We don’t know much about whether or where wind slabs formed during these recent storms, but given the wind conditions on Saturday and Monday, we suspect slabs developed along higher elevation ridges, in the tops of chutes, and near the base of cliffs. A nice dusting of snow could hide obvious wind slabs in some locations. 

    Look and feel for scoured slopes, drifts behind rocks, and sharp cornices to anticipate local wind patterns and potentially loaded slopes. As these slabs get older, they could be harder to trigger, but firm wind slabs can be notoriously difficult to assess. They’re most likely to release near convexities, on unsupported slopes, or in complex terrain.

    The wind often forms thicker slabs around rocky outcroppings. You're more likely to trigger a wind slab in wind-loaded terrain like this.

    Photo: Oliver Kramer

Avalanche Discussion

This last series of storms brought a decent amount of precipitation to the West Central zone, around 1.2-1.5 inches. However, weather stations showed little to no change in snow depth. Maybe somewhere, up higher, there’s a healthy amount of recent snow. What’s that elevation? Good question. At middle and lower elevations, it seems only a few inches of wet heavy snow accumulated. 

We’re only really concerned with the new snow over the 2/7 crust. Down low, that’s basically the surface. This crust may be firm and slick in some spots and could allow avalanches to slide easily. At Stevens and Snoqualmie Passes on Sunday observations reported a mid storm crust up to around 5500ft in the terrain. This could also help limit avalanche issues, if it exist in the West Central zone. 

Unfortunately, these storms didn’t improve travel conditions or coverage. Punchy snow, breakable crust, icy slopes, and numerous obstacles continue to make travel challenging and, in some cases, dangerous. Plan for extra time to deal with these “early season” conditions.

Regions covered