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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Triggering a larger avalanche remains possible in the eastern portion of this zone—the Little Wood drainage, Pioneer Mtns, and near Bald Mtn—where 16-20 inches of recent snow fell on a weak snowpack. Wet snow avalanches will become possible as the day warms up. These will be most likely on slopes getting hit by the sun, and on all lower elevation slopes.

Avalanche problems

  • Persistent Slabs

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

    The southern Pioneer Mtns (including the Little Wood drainage, Mormon Hill, and Swede Peak areas) as well as Bald Mtn near Ketchum, received 16-20” of dense snow since last weekend. This new snow fell on persistent weak layers that formed during the February dry spell and resulted in several large, natural persistent slab avalanches. Some of the slides were hundreds of feet wide (photo to right), failing at the interface between the new snow and the old rotten snow on shadier slopes. Today, you are most likely to trigger a slab avalanche where the wind has affected the snow, but slides large enough to bury people are possible in sheltered terrain too. 

    You may be able to trigger slides remotely: from flatter terrain above, below, or to the side of a steep slope. Choosing lower angled terrain is the only way to safely "manage" this problem. 

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Sunshine and warm temperatures in the forecast today put wet loose snow avalanches back on the menu. There are two main flavors you could find today:

    • At middle and upper elevations, loose snow avalanches could involve the recent snow that fell since the weekend. As the newer snow becomes moist or wet, it will have a tendency to sluff downhill. This will be more likely on E and W-facing slopes that are transitioning from dry to wet snow, but could extend into S aspects too.
    • At lower into middle elevations, the spring transition has lead to a snowpack that is wet to the ground. With a weak freeze overnight, the thin surface crust is likely to melt quickly as the day warms.  Where the snowpack is shallow and weaker, this type of wet slide could gouge down to the ground once it gets moving.

    Both are possible today on steep slopes—especially those getting direct sun. Wet slides often release naturally, so keep an eye on what's above you. I wouldn't expect either of these scenarios to produce large wet slides, but that's not to say that I'd want to get tangled up with one. 

Avalanche Discussion

We're solidly in the throes of spring. The weather can change from minute to minute, and you can find different snowpack conditions from one step to the next. These changes may not always mean an increase in avalanche hazard, but it's important to recognize when they do. Here's what I found yesterday:

As I left the car and ventured into the lower elevations, I found a spring snowpack that was wet to the ground. Luckily, cold temperatures overnight had created a surface crust that supported my weight. This crust will likely be thinner this morning, and as it gets thawed by valley temps reaching the mid-40s F, wet slides will become possible on very steep slopes. In the southern portion of the forecast area, the lower elevation snowpack—where it still exists—is thin and weak and wet slides could gouge down to the ground.

As I climbed into the middle and upper elevations, I finally found dry snow on northerly-facing slopes. Pokes of my ski pole revealed weaker, faceted snow about 12-14 inches deep. This layer formed during the February drought and was buried earlier this month. Snowpack tests didn't produce poor results, and I didn't see any other sign of instability. Still, I asked myself: "Where would this problem be worse?" The easy answer is where the storms since last weekend produced more new snow. The SE corner of the forecast area (the Little Wood drainage, the Pioneer Mtns, and near Bald Mtn) picked up 16-20 inches during these storms, and several larger, natural slides occurred as a result. Another area of concern is where recently-formed or older wind slabs sit atop this faceted weak layer.

Since it's my job and I'm a glutton for punishment, I also ventured onto sunnier aspects at middle and upper elevations. On E and W-facing slopes, I found that the snow that fell since last weekend was transitioning from dry powder to moist, sticky glop or consisted of a breakable crust. As the sun hits these slopes today, and the dry-to-wet transition proceeds, wet loose snow sluffs may become possible—especially on very steep, rocky slopes. 

While places where you could trigger a larger avalanche are mostly limited to the SE corner of the forecast area, my day yesterday was a reminder that there are smaller problems to keep your eye on. Never a dull moment in the spring!

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