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

While Sunday’s weather looks beautiful, it could create dangerous conditions with natural avalanches during the day. Plan your trip to travel and return early before these conditions develop. You don’t want to be under one of these slopes if it releases.

Avalanche problems

  • Loose Wet

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

    Mostly clear skies should help the surface freeze solid Saturday night. This will minimize any loose wet danger in the morning. Travel while the surface is still frozen or just beginning to soften. Once your boot sinks in past the ankle, the hazard is already on the rise. Rollerballs and fresh piles of fan-shaped debris tell you that natural avalanches will occur on similar slopes and potentially dangerous conditions are developing. While you might trigger one of these slides, the greater risk may come from snow falling down on you. As the surface crust breaks down, what were small loose wet avalanches may start to entrain more snow, grow large, and run long distances. Other zones around the region saw a few of these scarier loose wet slides on Saturday. Remember, rocky slopes above you may soften much faster than the lower angled and possibly shadier terrain you’re in. While a cool breeze and a few high thin clouds will fight to delay wet snow issues, we think the strong April sun and warm temperatures will eventually win and dangerous avalanche conditions will develop.

    (3/24/2022)

    Example: Once you're boot punches in past your ankle, it's time to start thinking about heading home. Dangerous conditions could be developing.  

    Photo: Dallas Glass

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    When we list cornice as an avalanche problem, conditions are ripe for them to fall down on their own. While predicting exactly when and where that may occur is nearly impossible, Sunday’s warm and sunny weather feels like a good bet. You could see cornices collapse or blocks of snow shed from rocky terrain. We don’t think this will be a very widespread cycle, but you don’t want to be under one of these features if it fails. Choose routes that help minimize the amount of time you need to spend below rocky terrain and overhanging cornices.

    (3/29/2022)

    Example: Cornices on some slopes are large and overhanging after a snowy April. They could fall down Sunday. 

    Photo: Andy Harrington

Avalanche Discussion

Despite the relatively warm air temperatures, Saturday night’s clear skies should allow most surfaces to freeze. Underneath tree cover, this likely won’t be the case, and you could see punchy wet snow or a thinner breakable crust first thing in the morning. With these clear skies, temperature inversions may form in some of the mountain valleys and passes. This could make it a bit chilly at the trailheads first thing in the morning but don’t worry, temperatures will quickly rise. With warmer air at mid and upper elevations, the snow could soften faster than you expect. There’s always a lot of uncertainty when talking about wet avalanche cycles following a snowy period. However, if Saturday’s avalanche observations are any indication, we anticipate Sunday will be more active or at least produce larger slides. 

We’re primarily worried about avalanches in the upper snowpack above the prominent 4/8 crust. You can find this layer 2.5-3.5 ft below the surface in most locations. If avalanches start to gouge and entrain deeper layers they could involve some or all of this snow. Fortunately, we aren’t generally worried about weak layers below the upper snowpack at this time.  

This is NWAC’s last daily avalanche forecast for the 2021-2022 winter season. Mt Weather Forecasts will continue until May 1. Make sure to check our Spring Avalanche Statement for information and travel advice. NWAC will continue to track snow and weather conditions. Large storms and/or widespread avalanche cycles may cause us to issue special avalanche bulletins, avalanche warnings, or other spring statements to keep you informed.  You can help your backcountry community by continuing to submit observations of avalanches, snow, and pertinent weather to our site. 

Have a fun and safe spring recreating in the mountains!

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