Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

The majority of avalanche activity should involve the recent storm snow on Monday. Use small test slopes or quick hand pits to look for cracking or failing blocks of snow. Slabs will be thicker and potentially more sensitive on the volcanoes or in wind-loaded terrain.

Avalanche problems

  • Storm Slabs

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

    Slab avalanches will be easier to trigger on convex features or in wind-loaded locations. Before committing to a slope, be sure to check the recent storm snow for interstorm layers and bonding to the underlying surface. You can use quick hand pits or uptrack tests as you travel to determine if there is heavy snow over weak snow or potential failure points. In areas with lesser storm totals, look for signs of the wind such as fresh cornices or new drifts to determine features to avoid. When in doubt, seek out lower-angled terrain.

    (12/8/2024)

    Quick hand pits as you travel can give you an indication of slab potential or weak points in the recent storm snow.

    Photo: Andy Harrington

Avalanche Discussion

We just wrapped up a nice little storm that brought winter back to the mountains of the West South. Storm totals vary across the zone, with the volcanoes receiving 1-1.5 feet and the crest coming in closer to 6-9 inches. Winds were a bit of a player during this one, so you may find that slabs formed on leeward slopes or near rocky outcrops. 

Observations are a bit limited, but NWAC forecasters near Crystal Mountain found roughly 10” (25cm) of storm snow sitting atop the 12/7 melt-freeze crust on Sunday. The height of snow and the thickness of the 12/7 both varied between northerly and southerly aspects - a result of last week’s warm and sunny weather.  Small column tests failed within the light new snow. A public observation from the White Pass area indicated a similar set-up. Crystal Mountain Pro Patrol reported several small storm slab avalanches during their morning mitigation work. While Rainier’s Nordic Patrol relayed a lack of avalanche activity and a ski-supportable crust at 5100’.

The weekend started wet, with rain falling above ridgecrest in most locations. This may have helped to wipe out the weak snow on and near the surface that was previously reported from Crystal Mountain down to Mount St. Helens. Still, keep it in the back of your mind if you venture toward high-elevation shaded slopes, particularly near the crest where less rain fell on Saturday.

This storm helped to recover some of our healthy early-season snowpack, but plenty of obstacles still exist. Open creeks, shallowly buried rocks and logs, and now a rain crust can slow your travel or worse. 

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