Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

You can trigger slides large enough to bury you on many slopes. Avalanche danger will rise throughout the day as more snow falls, with large natural avalanches becoming more likely throughout the day. Slides will be larger, more destructive, and easier to trigger as you climb elevation bands into terrain affected by the wind. Much larger slides breaking on buried weak layers remain uncomfortably likely and can be triggered from long distances away.

Avalanche problems

  • Persistent Slabs

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

    Local skiers remotely triggered a persistent slab avalanche near Ketchum yesterday (see adjacent video), and another group remotely triggered a large persistent slab avalanche in out-of-bounds terrain near Baldy two days ago. This slide broke 700' wide in terrain that had already been skied several times, was 4-8' deep in spots, and ran 1500' into a creek below. Weak layers in the snowpack were pushed closer to their breaking point by last week's storm.  Due to their depth, it is unlikely you will receive any warning signs, much like these skiers who had already skied this feature, before triggering a large, destructive slide on these layers.

    Avalanches that fail on these layers can break thousands of feet wide and send the entire season's snowpack downslope. These slides can wipe out swaths of mature timber and will be unsurvivable. These types of slides behave in ways that surprise even experienced users. These slides will break wide, wrapping around entire bowls and cirques. You can trigger these avalanches from long distances away from steeper slopes, including from flat terrain below large avalanche paths. Any of the new snow avalanches described below can trigger these much larger slides. 

    In the western portion of this zone, you'll find the early February weak layers buried underneath very dense and very heavy slabs. Triggering an avalanche on deeper weak layers is less likely, but any slide that breaks on them will be massive. Smaller natural and human-triggered avalanches can step down to these deeper weak layers. Slides that break on these layers can wipe out swaths of mature timber and will be unsurvivable.

  • Wind Slabs

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

    10-15 inches of new snow will fall by tonight on top of the 2 feet of settled snow that has fallen in this zone since last week, with periods of intense winds. You'll observe a wide range of instabilities involving the new snow, depending on the terrain you enter. Avalanches will be most likely in terrain that has been affected by the wind, which is most of the terrain at middle and upper elevations in this zone. 

    Expect stiffened, denser SLABS in more exposed locations near ridgelines — these will be more difficult to identify with lighter, fluffy snow on top. In this same exposed terrain live many large CORNICES, which you should give wide berths when traveling ridgelines. These wind features will serve as effective triggers for avalanches in terrain below them if they fail either naturally or by human triggering. Any one of these types of slides could be large enough to bury you, and can serve as an effective trigger for deeper, more destructive avalanches described below.   LOOSE SNOW avalanches are most likely to be triggered in steep terrain, and can be triggered even in sheltered areas. These will run far and fast on slick crusts, gaining speed as they race downhill. 

    (2/27/2024)

    This slab avalanche was triggered from 50 ft away on a low-angle ridgeline. It broke widely in wind-drifted snow on a thin layer of facets above a crust. Cracks extended another 100' cross-slope beyond the crown. Smiley Ck, ENE @ 9,100'.

    Photo: Sawtooth Avalanche Center

Avalanche Discussion

Today we are getting another punch of water with 10-15 inches of new snow falling by this evening in this zone, adding more stress to multiple weak layers in our snowpack. In recent days, multiple large human-triggered and many natural persistent slab avalanches ran. You are likely to trigger slides similar to these today. Danger will rise across this zone throughout the day, and I wouldn't be surprised to see large natural avalanches breaking near the ground in this zone by sunset.  Today is not the day to be hanging out underneath large slide paths. In areas like the Baker Creek drainage that will be more dangerous / getting more snowfall, expect unusual and notable avalanches to occur even at middle elevations.  New snow instabilities like newly forming storm slabs as well as old and new wind slabs will be effective triggers to step down to these deeper layers to create larger, more destructive slides today. Each of these recent avalanches gives us data points to keep in mind when heading into the mountains today:

  • Local skiers remotely triggered a persistent slab avalanche near Ketchum yesterday. Similar to all other recent, reported human-triggered slides, this party received no warning signs until they were immediately in the terrain they triggered the slide from, which broke just 50' below them. Their thoughts they will be carrying with them into the hills after this: "One of the starkest takeaways was the incredibly short spatial distance in which the snowpack went from feeling "safe" to not at all safe."
  • Skiers remotely triggered a large persistent slab avalanche in out-of-bounds terrain near Baldy two days ago. This slide broke 700' wide in terrain that had already been skied several times on a E aspect near 8100', was 4-8' deep in spots, and ran 1500' into a creek below. Multiple skiers had descended this slope before this slide occurred, not receiving any warning signs. This slide occurred in terrain outside the ski area boundary commonly called Sunspot Bowl. Out-of-bounds (OB) terrain, even in close proximity to the resort, is consequential and not mitigated for avalanche hazards by ski patrol. Any skier or boarder choosing to enter OB terrain should treat it as entering the backcountry and have the appropriate avalanche gear and training. While not receiving any obvious indicators of instability, slides like these remain likely. 
  • Sun Valley Heli remotely triggered a large persistent slab avalanche from an adjacent slope two days ago, as well as noting multiple other D2 slides that ran naturally. Each of these slides ran beneath the new snow,  proving our newest weak layer to be reactive. SVHS also intentionally triggered a couple of large cornices above complex NE-facing terrain near 9800'. These failing cornices triggered large avalanches on the slopes they impacted below, which ran on facets near the base of the snowpack. This reminds us to be mindful of cornices both in the terrain we are traveling through and above us.
  • Ben observed several large to very large naturally occurring persistent slab avalanches in the Boulder and Smoky Mountains that ran during the past storm. I spotted more of these in the Boulders and Smokys yesterday, with Scott noting more of these in the Sawtooths. It is more than likely that many more similar slides have occurred throughout our forecast area. 

This week will provide ample opportunities for high-quality skiing and riding. This being said, knowing that avalanches like these remain likely should be driving your trip planning and decision-making headed out into the hills. Luckily enjoying soft powder flowing over the hood, or snow in your face does not require entering avalanche terrain.

Regions covered