Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

Avalanche danger should peak Sunday night in the West South and could linger into Monday morning. Avalanches will be most likely in places that receive more than a foot of new snow and in wind-loaded terrain. Give the snowpack time to heal and stay off of slopes over 30 degrees.

Avalanche problems

  • Storm Slabs

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

    This storm will end on a cooling trend, which should help some of the snow form right-side-up. However, heavy precipitation rates and strong winds Sunday night could build weak layers within the storm snow. These slabs might just be hidden by the inviting powder Monday morning. 

    You may trigger avalanches on these storm layers or at the 2/24 interface. Prior to this storm, firm crusts, surface hoar, facets, and irregular surfaces were reported. Weaker snow was typically present on shaded aspects above 5500ft. If an avalanche fails at the 2/24 interface, it may trigger easily or break widely. Make sure to check all the way down to this layer as you observe the new snow. Near places like Mt Rainier that receive more snow, this may mean small slopes and uptrack tests don’t fully assess all the storm snow, and you may need to stop and dig. With all the new snow and the potential for a persistent weak layer, this is a good time to give the snowpack time to adjust. Use lower angled, wind-sheltered, and treed terrain to help reduce your risk. 

    At lower elevations, warmer temperatures early in the storm should help the snow stick to the old surface. However, avalanches could still occur on steeper slopes and unsupported features.

    (1/26/2024)

    Example: Shovel tilt test are a great way to look at storm snow layers. 

    Photo: Dallas Glass

Avalanche Discussion

A significant winter storm will continue to bring snow to the West South zone Sunday night and into Monday. Expect the most dangerous conditions first thing in the morning. As the storm eases, the snowpack should start to heal, but this will take time. Cold temperatures and the possibility for surface hoar/facets could mean this takes longer than normal. 

This storm should bring 2 feet of snow or more to the volcanoes and White Pass by Monday afternoon. For places that receive less snow, you may see smaller avalanches and slightly lower danger. In these locations, pay particular attention to wind-loaded terrain, where slabs could be thicker. 

A strong cooling trend should leave some light fluffy snow on the surface. This could do two things. 1. It may hide the underlying slabs and make them hard to spot. 2. It might result in small loose dry avalanches in steeper terrain, even in the trees. 

A few sun breaks are possible Monday afternoon, particularly near Crystal and White Pass. The cold temperatures should help limit any warming. However, if the sun comes out, you might see a few small natural loose avalanches as snow sheds from rocks and trees. 

On shaded aspects, the upper snowpack still contains a few potential weak layers (2/19, 2/14, EFC). In some places, you may find facets, surface hoar, or crusts. Significant wind events made these layers highly variable even within a local area. We don’t expect avalanches to step down into older snow, but they may in isolated locations. Take these much bigger slides into consideration if your travels leave you exposed to large avalanche paths at middle and upper elevations.

Regions covered