Avalanche forecast

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Sawtooth Avalanche Center
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Avalanche danger

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

Triggering an avalanche large enough to bury a person would require a dose of bad luck, but remains a possibility today. Weak layers of snow buried 3 feet deep have proven to be less reactive here than in our other zones. You'll be most likely to encounter this problem in terrain where the wind has stiffened the snow surface and added weight. In these same areas, thin fresh wind slabs have formed in the past two days. Look for signs of wind drifting to help you avoid this problem.

Avalanche problems

  • Persistent Slabs

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

    Weak layers of snow buried 2-3 feet deep have proven to be less reactive in this zone than in neighboring areas. On Friday, Chris went looking for this problem north of the highway. He found it in some of his snowpits but not in others. On an east-facing slope he found a thin layer of facets on top of a crust, all buried beneath a 3-foot thick slab. The block did not fail during standard loading tests in his snowpack tests, but he was able to get it to break cleanly with some extra force.

    Dealing with persistent weak layers is tricky business, particularly as they become more deeply buried. Snowpack test results become more difficult to interpret and obvious signs of instability are absent. The first clear sign of an unstable snowpack may occur when you trigger a large avalanche. 

    ADDITIONAL DISCUSSIONThe days since the recent storm have been much colder than average. Last night's temperatures were the warmest we've seen in a week. If the sun comes out for longer than expected today we may see some wet snow issues develop. Keep an eye on the condition of the snow surface. If it starts to get wet or you are seeing wet balls of snow forming and rolling downhill it is time to think about moving to an area where the snow surface is colder and drier. 

Avalanche Discussion

Ahhhh, April. A time of good stability, right? Not this year, unfortunately. Skiers and riders have triggered slab avalanches on six out of the past eight days. For perspective, a total of 27 human-triggered avalanches have been reported to us throughout the entire season. Pause and let that sink in for a moment. Nearly one-quarter of the reported human-triggered avalanches occurred last week. 

These avalanches have occurred across much of our advisory area but the layers responsible have proven to be variably reactive. In some places we are seeing clear signs of instability (unstable snowpack test scores and both natural and human-triggered avalanches) while in others they appear to be somewhat inert. This irregular pattern of activity makes these layers even more challenging to deal with. But, with weak layers buried 1-3 feet deep, the consequences of being wrong in your stability assessment can be quite high.

Today, I'd strongly advise that you let the snowpack guide your terrain selection and not the calendar. We are dealing with a snowpack that is behaving more like it is February than April. Its easy to be lulled into the false sense of security at this time of year, particularly after the long periods of relatively good stability that we saw during February and March. But the snowpack doesn't care what the date is and you shouldn't either. In order to avoid the hazards posed by the type of avalanche problems that we are dealing with we need to travel accordingly. Be alert to the terrain you are in and the terrain you are below. Think about the consequences of triggering and being caught in a large avalanche. Your safety and that of your riding partners demands that you ignore the calendar and focus on the snowpack.

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