Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

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

If you are taking your new toys out to play in the mountains on Sunday, be prepared for cold temperatures and lots of light fluffy snow. Be leery of slopes where the wind may have drifted the snow into slabs and avalanches are more likely. Plan your travel to avoid consequential slopes over 35 degrees where loose snow could sweep you off your feet.

Avalanche problems

  • Wind Slabs

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

    Gusty winds on Christmas Day likely formed another round of Wind Slabs in the West South. These slabs may have been easily identifiable by looking for visual clues such as textured surfaces or actively blowing snow on Saturday. On Sunday, as the winds calm and more snow falls, these slabs may become hidden from view. You should take the time to feel for a change in snow depth or firmer snow below the surface as an indication that you are in wind-loaded terrain. Identifying the predominant wind direction by looking for freshly formed cornices or drifting behind natural features can give you clues as to the aspects where you need to take extra care. Wind Slabs like to form on the lee sides of ridges, near the base of cliffs, on the sides of gullies, and in confined rocky chutes. Wind loaded terrain continues to be the most likely location for you to trigger a large avalanche and now we potentially have multiple rounds of Wind Slabs buried under fresh snow. If you suspect a slope to be wind-loaded, best to give it a wide berth and choose an alternate path.

    (12/23/2021)

    Intense blowing snow was encountered Thursday (12/23) on the Paradise parking lot. When you see wind transported snow, anticipate wind slabs in near by terrain. 

    Photo: Mt Rainier Rangers

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    There have been multiple reports of shallow Storm Slabs around the West South the past few days. Their distribution has been difficult to pin down, but these slabs have generally been soft and many propagated only a short distance. In some cases, these avalanches have been able to entrain additional soft snow as they descended. You could encounter an avalanche in the new snow and think that it more closely resembles a Loose Dry avalanche. Regardless of what you want to call it, the take home point is that there is a lot of storm snow and you should be prepared to manage loose snow moving downhill on slopes over 35 degrees. Be aware of what is above you at all times and use test slopes as a good indicator of slab potential and how the soft snow may react to your weight. Using uptrack tests or quick hand pits to look for cracking or blocks of snow failing can also give you an indication that the snow has slab properties.

    (12/25/2021)

    This small feature near White Pass naturally avalanched before filling back in with storm snow. The crown was 8-10" deep and propagated the width of the feature. (SW 4100' 45+ degree feature)

    Photo: Dallas Glass

Avalanche Discussion

Over 3 feet of snow has fallen in many areas of the zone since the storm parade began on 12/22. During this period, the West South zone had the first two NWAC weather stations to record a snow depth of 100 inches for the season! Chinook Pass was the first station to reach the milestone on 12/23 with Paradise following suit the next day, 12/24. Throughout many areas of the zone, this storm snow is generally well bonded to the Solstice Crust that can be found anywhere from 2-3 feet below the surface. Although this crust is not prominent in every location, we anticipate most avalanche activity to occur above this interface. 

We are lacking direct observations from the southern half of the zone, where the storms may have hit harder. If you are recreating in these areas, such as Mt. Adams or Mount St. Helens, you should take a look at the Mt. Hood forecast to help paint a better picture. We’d also love to hear what you’re seeing out there, so send us an observation.

On Sunday, the temperatures are expected to plummet to colder than normal. Lower elevation hikes could have more snow or ice than usual so be prepared for winter travel no matter where you are recreating. With so much light and fluffy snow, falling and not being able to get up is a real hazard. Give tree wells a wide berth, keep your partner in sight, and learn more about snow immersion hazard here.

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