Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

You are most likely to encounter avalanches in areas where the wind has added weight to weak layers in the snowpack. These weak layers exist in the upper snowpack and near the ground. Triggering very large avalanches failing on weak snow at the base of the snowpack remains a possibility and would be an almost certainly unsurvivable event. You can significantly reduce your risk of triggering an avalanche by choosing terrain that is sheltered from the wind. 

Avalanche problems

  • Wind Slabs

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

    Strong winds during last week's storm created a patchwork of scoured and drifted slopes. Where the wind was building slabs it did so on a variety of surfaces. These slabs have had a bit of time to bond to the surfaces that they were deposited on but there are still places where you can trigger them. On Sunday, on an off-duty ski day in the Sawtooths, my partner and I intentionally triggered a few small wind slabs in steep, alpine terrain. This type of terrain is unforgiving and you would not want to be caught on the wrong side of one of these slabs. 

    In this zone, these wind slabs are most concerning where they overlap with the persistent slab problems described below. Stiff slabs on top of weak layers (those in the middle of the snowpack as well as at the base) are never a good combination. 

    ADDITIONAL DISCUSSION A crust+facet combination exists underneath last week's storm snow on slopes that directly face the sun (southern half of the compass). This layer produced a number of large, natural avalanches in this zone during the recent storm:

    •  SW Bowl of Galena Peak (photo above/right)
    • In the Boulders near Mushroom Ridge, and one
    • Behind Horton Peak in the Pole Creek drainage (photo).

    Time will tell how long this layer will be problematic, but I'll be particularly leery of slopes where this layer exists for the next bit.

    (1/8/2022) This large natural avalanche occurred in the wind-affected SW bowl of Galena Peak. It likely ran on the interface between the old snow and the recent storm snow, which consists of a facet/crust layer on some steep, sunny slopes. 10,500', SW. Photo: T. Haskins

  • Persistent Slabs

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

    Early season snowfall left us with a layer of weak, sugary snow at the base of our snowpack. This layer is most concerning on shaded slopes at middle and upper elevations. Chris was on Titus Ridge on Friday where he found the layer buried over 4' deep. He described the snow underneath as  "still as weak and sugary as ever."  The slide pictured at right/above, which occurred near Galena Summit, appears to have failed on this weak snow. 

    The presence of this weak snow continues to strongly influence the type of terrain that local professionals (myself included!) are willing to consider traveling in. What type of terrain are we taking off the menu? Very steep (>35 degrees), rocky slopes where the wind has created a variably thick snowpack. This snowpack variability (wind drifting in places and scouring in others) creates thinner portions of the overlying slab where triggering a slide is more likely. Triggering a wind slab or a collapsing cornice are also "good" ways to impact this weak snow.

    If I was forced to enter big, consequential avalanche terrain in the alpine somewhere in our Forecast Area, this would be the last Zone I'd pick.

    (1/8/2022) Natural avalanche near Titus Ridge on the divide between the Big Wood and Titus Creek. Judging by the depth, it looks to have failed on weak October snow near the ground. 9400', N. Photo: T. Haskins

Avalanche Discussion

WEAK LAYER and SLAB DISTRIBUTIONAfter a wild month of nearly continual snowfall and wind we find ourselves in a period of clear skies, cold temperatures, and light winds. The calm after the storm. This is a great time to take stock of the state of the snowpack and think about the variability that we are seeing across our area. The first two rounds of storms (mid-December and near Christmas) brought a big helping of snowfall to most of our region. A bit more snow fell in our northern and western mountains (Banner Summit area, Sawtooths, Western Smokys, Soldiers) but the mountains above the Wood River Valley and those on the eastern side of the Big Wood and Salmon Rivers (Pioneers, Boulders, White Clouds) picked up their fair share. These storms buried a layer of weak snow that had stuck around after our first big snowfall of the year in late October. This October snow was preserved on shaded slopes at middle elevations and most slopes at upper elevations. The December snowfall pattern left a thicker slab of snow on top of this weak snow in the more favored areas (north and west) and a thinner slab to the south and east. Simple enough.

The most recent storm (January 3-7) heavily favored the northern mountains and left the good people of the Wood River Valley wondering, "storm, what storm"? In areas favored by this storm, we saw widespread avalanches related to the new snow (wind slabs, storm slabs, loose snow avalanches) as well as a pattern of activity that pointed to the involvement of a weak layer buried at the base of this storm snow. This layer appears to be at its worst on slopes that face the south half of the compass, where it exists as a subtle crust with facets above and below. In the areas favored by this storm, this layer is buried 2-3.5' down under a meaty slab of snow. In the areas that were missed by this storm, this weak snow is much closer to the surface. This is starting to feel a little more complex.

If we mentally zoom back out, we can see that we have patterns of weak snow and slabs that vary widely by aspect and elevation, and between forecast zones. If you want to completely avoid areas where either of these weak layers exists you will have to do quite a bit of thinking and planning. As the likelihood of triggering avalanches on these weak layers slowly decreases and the Avalanche Danger slowly comes down, we find ourselves in a tricky place. Avoiding avalanche terrain is pretty simple, but deciding when and where to engage with avalanche terrain is very complex. When you are out in the mountains today, think about these patterns and whether or not these weak layers exist in the terrain you are playing in. The danger may be MODERATE in all of our zones, but the snowpack is different everywhere you go. Whether or not you choose to enter avalanche terrain is up to you, just be sure you know what sort of dragons you are choosing to engage with.

Regions covered