Avalanche forecast

Soldier & Wood River Valley Mtns

Sawtooth Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 7 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

It remains possible to trigger an avalanche on slopes with wind-stiffened or drifted snow. Although buried weak layers are improving, lingering signs of instability indicate we're not out of the woods yet. Avoiding steep slopes with evidence of wind drifting continues to be the best approach.

Avalanche problems

  • Persistent Slabs

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

    Regular readers of the forecast have heard plenty about the layer of surface hoar buried 1-2 feet deep throughout our area (read more about it in the Discussion below). It was responsible for human-triggered avalanches in the Soldiers last weekend. Although this zone received less recent snowfall then our zones to the north, it still remains possible to trigger an avalanche in areas where recent or past winds have drifted snow.

    Wind-loaded slopes are more common near the Smoky Crest around Dollarhide Summit and in the Soldiers than in the mountains surrounding the Wood River Valley, so the chances of finding trouble increase as you move west in this zone. Yesterday in the Soldiers, Scott found that wind-affected slopes remained sensitive during snowpack tests (see video). Observations like these indicate it's still possible to trigger an avalanche, and avoiding steep slopes with evidence of wind drifting continues to be the best approach.

Avalanche Discussion

In last Wednesday's Digging Deeper talk about Understanding Weak Layers, we discussed how to tell when buried weak layers have improved. Did I provide a clear answer? No, because there isn't one. In the life cycle of a persistent slab problem, this is the most dreaded time. Signs of instability begin to wane, and the desire to break out of the mellow terrain you've been playing in begins to weigh heavily on your decision making. From a pure stability standpoint, conditions were more dangerous last weekend. But if you throw humans into the mix, I'd argue it's more dangerous right now.

While our area is known for some wicked facet layers, a widespread surface hoar layer isn't particularly common. Sure we get them occasionally, but they tend to be more "pockety" in nature and rarely produce such impressive avalanche activity as the one we have now. Surface hoar can be extra tricky—in fact, some studies have shown that it's the weak layer that produces the most avalanches that catch professionals. 

So how do you tell if a buried weak layer's improved? In the Digging Deeper talk, I said the key factor was time. Time since the last loading event (snowfall or wind), and time since the last sign of instability, and then a bit more time. With moderate to strong winds in the forecast today, and a few significant signs of instability still being reported, I don't believe we're there yet. So my advice is this: be patient. Even if you think conditions are getting better, what harm is there in giving it a little bit more time?

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