Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 4 years ago.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

Highlights

You’re most likely to trigger an avalanche in wind-loaded terrain on Wednesday. Unfortunately, some of these slabs may be hiding underneath soft inviting powder. Be leery of any steep slopes below sharp cornices or near drifts at all elevations.

Avalanche problems

  • Wind Slabs

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

    Very windy weather likely formed deeper and firmer slabs on the lee sides of ridges, along the base of cliffs, and in the tops of chutes. However, as the winds decreased and snow continued to fall, some of these slabs may have been buried under soft fresh snow. That means they could be tricky to spot and harder to avoid. 

    Look for larger clues like sharp cornices and drifts to anticipate wind-loaded aspects. In these areas, assume wind slabs exist until you can confidently rule them out. 

    Ease into the terrain by traveling on smaller and lower consequence slopes first. Look for cracks and feel for firmer hollow snow to help indicate wind slabs are present. If you see these clues, stay off of slopes over 35 degrees in similar terrain.

    (2/18/2023)

    Wind features in the Tatoosh Range near Mt Rainier highlight wind transport. 

    Photo: Susie Glass

Avalanche Discussion

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

We’re just coming out of a stormy few days in the West South zone. While this system may not have played out exactly like we thought, it still brought a healthy round of snow to most of the zone. Strom totals since 2/19 range from 3-18 inches and counting. Due to the stormy weather, backcountry observations have been limited, resulting in lower confidence in the current conditions. 

Given the strong cooling trend at the end of the storm, we expect generally right-side-up storm snow in wind-sheltered terrain. This may result in small loose avalanches or sluffs on very steep slopes. If the clouds thin or the sun comes out, you may see some of these smaller slides occurring naturally near rocks and trees. 

We think any avalanche activity will stay within the recent storm snow. However, you could encoutner an isolated large avalanche failing on older layers like the 2/17 or 2/13 interfaces. This would probably take a more significant trigger like a cornice or small avalanche to occur. 

One exception to this forecast is the Crystal area. Significantly less snow fell in this location than in the remainder of the zone. In this area, you may find much lower avalanche danger with only isolated wind-drifted pockets of new snow.

Regions covered