Avalanche forecast

West Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Backcountry travelers should still be wary about moving across or below steep slopes of wet snow. You are most likely to encounter an avalanche on southerly slopes that become even more unstable under a strong sun. High freezing levels will sustain wet avalanche danger into the weekend.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3

    Though the rain has ended, high freezing levels and potentially strong sun on Friday will delay the snowpack refreeze we hope for after rain events. Danger from loose wet avalanches, wet slabs, glide avalanches, and falling cornices are still factors to consider in avalanche terrain until we get a significant decrease in temperature. Wet slab and glide avalanches can happen long after heavy precipitation ends as water continues to percolate through and weaken the snowpack.

    Avoid traveling under sagging cornices, glide cracks that indicate the entire snowpack is slipping on the ground below, large, unsupported blocks of snow on rock faces, or slab avalanche hangfire. These are not dangers that can be precisely anticipated or “managed" - all you can do to reduce risk is stay away from steep terrain features that could still produce large, wet avalanches. Though the likelihood is low any of these hazards will release naturally in terrain above you, the consequences would be devastating.

    Smaller but still dangerous loose wet avalanches could be triggered in steep terrain where you are skinking past your ankles in wet snow.

    (1/11/2022) Naturally triggered wet slab avalanche on a south aspect near Excelsior Peak at 5100'.

    Photo:  NWAC Public Obs

Avalanche Discussion

Telemetry across and adjacent to the West Central has recoded anywhere from 4.0” to 7.0” of precipitation from January 10th through midday on the 134th. It fell nearly all as rain except for at the highest elevations. The rain fell on a cold, dry snowpack near and above treeline and triggered a natural avalanche cycle across the Cascades consisting of loose wet, wet slab and glide avalanches.

Three days of rain plus high freezing levels into the weekend have us on guard about the state of the snowpack. Lots of rain water free-ranging through cold snow layers and freezing levels of up to 9000' in January make for an unusual setup. Unusual weather makes for an unusual snowpack with makes for unusual avalanches. With this in mind take nothing for granted the next few days when it comes to evaluating risk in avalanche terrain.  

If you make it to the alpine in good weather on Friday, you may encounter unstable storm and wind slabs in the highest terrain. Assume more dangerous avalanche conditions if you find dry new snow that is rapidly warming with sun exposure and/or very high freezing levels.

Regions covered