Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Thu
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

Small natural or human-triggered wet loose avalanches are possible on steep slopes receiving sunshine. Use caution in steep terrain near terrain traps like cliffs and creeks. Don’t let one of these small slides catch you off guard in high consequence terrain. 

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Continued warm temperatures and sunshine will weaken the snow surface.  As it becomes wet and unstable, you may see piles of rollerballs or very small loose wet avalanches originating from very steep and often rocky slopes. This is most likely on the volcanoes which collected more recent snow than other parts of the forecast zone. The shallow accumulations of new snow should prevent these slides from becoming significant in most locations. However, since this snow sits over a crust, some of these slides may run far or fast. Don’t let one of these small avalanches surprise you if you travel above a cliff, gully, or creek.

    (3/12/2021) Example: Rollerballs like this are a great sign that the snow surface has become wet and unstable. Photo: Robin Pendry

Avalanche Discussion

Warm temperatures impacted the West South zone Tuesday. Reports from near Crystal suggest that the warming resulted in little more than some roller balls on the surface, however, the volcanoes have a bit more snow to work with, so the possibility of small wet loose avalanches persists. Wednesday should be warm, but increasing clouds may help limit how quickly the snow surface weakens. Snowfall totals from Sunday vary around the West South. You’re most likely to see real avalanches when you find more than 4” of new snow over the most recent crust. Weather stations near Paradise, Chinook Pass, and Sunrise indicate storm totals close to that amount. In other locations, minimal new snow and a strong upper snowpack should create generally safe avalanche conditions. 

Strong winds during the storm likely formed isolated pockets of wind drifted snow at upper elevations. These thin slabs could linger especially near the base of cliffs or in confined chutes. Look for small drifts or textured snow surfaces to anticipate which aspects and features may hold wind-loaded snow. Use caution around these shallow slabs in high consequence terrain. 

While the weather may feel like spring, the snowpack has not yet undergone its transition. Below the recent snow a dry, cold, and “winter-like” snowpack still exists. You can still easily identify many of our recent storm layers, crusts, and interfaces. As we enter this stretch of warm and sunny weather, cornices may fail, snow will shed from rocks, and unpredictable glide avalanches could occur. Don’t let a spring-time mindset shortcut your decision-making process. Pay attention to the terrain above you and remember it may bask in the warmth of the sun even as you shiver in the shade. 

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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