Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

The potential for very large deep avalanches continues to haunt the West South’s snowpack. It’s impossible to tell if any one slope will or will not slide. The only option is to avoid big avalanche paths. Natural wet avalanches and cornice falls will be a hazard unto themselves but could also act as triggers for slopes below.

Avalanche problems

  • Deep Persistent Slabs

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

    Deeper weak layers continue to linger in the snowpack 3-6 ft below the surface. When these layers formed, periods of sunny weather and several strong wind events created a highly variable snowpack with almost no discernible pattern. Now, we’re dealing with the consequences of these buried weak layers. Even if you dig a snow profile, it may or may not represent nearby terrain. 

    Since it’s nearly impossible to tell if any particular slope will slide, the only choice is avoidance. With these layers being buried so deep, tracks on a slope aren’t a good sign of stability. In fact, the snowpack might not give you any signs that you need to tuck tail and run until the whole slope avalanches. 

    Large triggers like collapsing cornices and other avalanches could trigger these big slides. In the West South zone, avalanches have generally occurred above 5500ft on N-SE aspects.

    A very large avalanche spotted from Crystal near the Cowlitz Chimney's of Mt Rainier. (3/6/2024) Photo: Chris Pleasance

  • Loose Wet

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

    Cold temperatures, a cool breeze, and a surface crust on southerly aspects will delay the wet loose issue on Thursday, but ultimately sunshine and warming temperatures should win. You may find wet punchy snow on steep sunny slopes that may slide downhill. Some slopes likely avalanched during Wednesday’s sunny weather, but if you start to see new rollerballs or snow shedding from rocky faces,  natural slides may occur on similar slopes. Most of these avalanches should stay small, but they could still carry you over a cliff or into a creek.

    (2/23/2024)

    Example: Rollerballs and wet loose avalanche debris below a very steep rocky slope at lower elections. 

    Photo: Dallas Glass

Avalanche Discussion

Yet another spring-like day is instore for the West South zone. Cold temperatures and some clouds could delay some of the hazard. As things heat up, you may see snow shed from rocks or a few cornices collapse. While not huge, these overhanging waves of snow are the largest they’ve been all year. They could trigger slides on the slopes below. 

With all the sunny weather this week, the snowpack is once again becoming aspect dependent. Crusts formed on many steep southerly slopes, particularly at lower elevations. Higher in the terrain and on shaded aspects, the surface remains cold, dry, and loose. A few lingering pockets of wind-loaded snow could exist along exposed ridges but should be fairly isolated in the terrain. 

Last week’s recent storm snow is generally cold, dry, and right-side-up. Below all this deep powder you’ll find the Early February Crust and other layers just above it. These persistent weak layers are often facets and are suspected in many deep avalanches around the zone late last week and into the weekend. Several more big crowns were spotted near Mt Rainier on Wednesday. While avalanche activity seems to have decreased in the West South, recent slides are suspected on the same weak layers in the Stevens Pass and East Central zones Tuesday. This layer was also confirmed in the avalanche fatality at Darland Mt in the East South zone last Friday. If you dig, look for sugary snow at or just above the EFC.

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