Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Very large avalanches this week, a well-known weak layer in the snowpack, and continued mild weather will maintain dangerous conditions. You can reduce your risk by staying in simpler and smaller terrain and limiting the time you spend underneath big steep slopes.

Avalanche problems

  • Storm Slabs

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

    The mild weather is almost certainly helping these storm slabs heal. However, fluctuating temperatures, periods of stronger winds, and a few sun breaks left several potential inter-storm weaknesses depending on aspect and elevation. Hand pits and small slopes can demonstrate how the snow will react to your weight. 

    As storm slabs become less likely, we often start to focus on features like convex rollovers, the base of cliffs, unsupported terrain, and wind-loaded pockets where avalanches will be easiest to trigger. Be particularly leery of slopes that end in terrain traps like tree fences, cliffs, or creeks where even a small avalanche could kill you.

    (1/25/2024)

    A recent avalanche in the Crystal Backcountry. Super Bowl, NE, 6100ft. 

    Photo: Crystal Mt Ski Patrol

  • Loose Wet

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

    A little cooling and less rain should help reduce the chance of wet avalanches on Friday. However, the upper snowpack is a hot mess at middle and lower elevations. Wet punchy snow could still result in avalanches, particularly in very steep, rocky, and unsupported terrain. Unless there’s a crust protecting the wet snow, you might still cause an avalanche. Don’t let one of these “push-o-lanches” carry you over a cliff or into a creek.

    (1/22/2024)

    A small wet loose "push-o-lanche" on east peak at lower elevations. 

    Photo: Dallas Glass

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    We received reports of at least 3 very large avalanches in the West South zone this week. There’s no better sign of instability than recent slides. And, that’s about the only real clue you might have. 

    Several older crusts with weak sugary facets exist in the middle snowpack. Some of these date all the way back to the Soltice in mid-December. With layers this deep, they often won’t talk to you, crack, or whumpf. Smaller slides, failing cornices, or hitting just the wrong spot could cause the whole slope to come unglued. Make sure to talk about the high consequences of this complex problem before you enter bigger terrain.

    (1/24/2024)

    You can see the crown from the initial wind slab in the upper left, that then triggered this deep slab avalanche. 

    Photo: Crystal Mt Ski Patrol

Avalanche Discussion

The dangerous conditions in the West South zone continue to be more about the complexity and consequences rather than the likelihood of any one problem. In fact, each of these avalanche concerns should be slightly less likely on Friday, given the relative break in the weather. While things could be quieter, the lull in the weather won’t allow the danger to drop. 

On Thursday, we received reports of an avalanche in the Crystal backcountry (NE, 6100ft). While it doesn’t appear this slide occurred on 1/25, it is recent and sits lower in the terrain than expected. This slide adds to the list of several other notable events from Crystal and Mt Rainier this week. 

Since 1/20, storm snow totals around the zone vary widely from 1-2.5 feet. During this time, rain reached well into the middle elevation bands for periods of time and may have left crusts within the storm snow. While you can find wet snow at or near the surface, the bulk of the snowpack remains cold, dry, and layered, despite the recent mild weather. Several crusts (1/8, 12/30, and Solstice) can all still be identified. Deep slab avalanches are believed to have occurred on these layers in all corners of the zone stretching back to early January. 

This could get scary Friday night as we shift from mild and wet to hot and soaked. Expect avalanche conditions to rapidly change, with large natural avalanches occurring as rain reaches higher into the mountains. This won’t be a good weekend to go winter camping anywhere near avalanche terrain.

Regions covered