Avalanche forecast

Galena Summit & Eastern Mtns

Sawtooth Avalanche Center
View on map

Avalanche danger

Sat
Alpine
4 · High
Treeline
4 · High
Below
4 · High
Open full map
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Heavy snowfall and wind-drifting are creating very dangerous avalanche conditions. Natural and human-triggered avalanches are almost certain. Stay off of and out from below all steep slopes. Avalanches can be triggered remotely—from below, above, and to the sides of steeper terrain.

Avalanche problems

  • Persistent Slabs

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

    Today's snowfall and wind-drifting are stressing weak, faceted snow buried over 3' deep. This weak layer has been the culprit in almost all of the avalanches we've observed this season. Continued heavy snowfall is pushing this weak layer to the breaking point, particularly where the snowpack is thinner. This avalanche occurred yesterday above Titus Lake near Galena Summit. It was likely triggered remotely from the low angle ridgeline above. 

    As snow piles up, smaller avalanches failing near the snow surface are likely. These slides can trigger larger persistent slab avalanches as they move downhill. Very large avalanches may run into valley bottoms—avoid all avalanche terrain. Remotely-triggering slides, from flat terrain below steep slopes, is a real possibility. 

    (1/28/2021) Avalanche above Titus Lake that was likely remotely-triggered from the ridge above.

  • Storm Slabs

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

    This zone has received up to 3' of snow (1.2-2.4" SWE) since Tuesday night. Air temperature has continued to warm slightly as the snow piles up which aids in the formation of top-heavy slabs of snow on many aspects. These slabs are forming on a variety of weak snow surfaces including facets, crusts and facets, surface hoar, and wind-hammered ice. Observers in the Soldiers, the Wood River Valley, and the Sawtooths (photo) have found very sensitive slabs of new snow, failing on a layer of facets above a crust.  

    Moderate to strong SE wind has moved a substantial amount of snow at all elevations. Expect slabs to be thicker, stiffer, and more dangerous in windier terrain. Areas of wind-drifted snow may be hard to identify due to low visibility and continuing snowfall. This problem will become more dangerous as snow and wind continue throughout the day. These slides have the potential to "step-down" causing avalanches to fail on more deeply buried weak layers near the ground (see Persistent Slab problem).

    (1/28/2021) Cracking in cornices adjacent to an avalanche near Galena Summit.

Avalanche Discussion

AVALANCHE WARNINGS are in effect for the Sawtooth & Western Smoky, Galena Summit & Eastern Mountains, and Soldier & Wood River Valley Zones.

Very dangerous avalanche conditions exist. Large, destructive, natural, and human-triggered avalanches are near certain. There are a host of scenarios that could send large avalanches hurtling down steep slopes today. Our snowpack has touchy weak layers under the recent storm snow, as well as a remarkably weak foundation of faceted snow. Expect avalanches to occur on many slopes, potentially breaking in unusual locations and wider than expected. 

Yesterday's observations were limited by difficult travel and poor visibility. Despite that fact, we didn't need to look for avalanches as much as we just needed to stay out of the way. Here are some notable events from yesterday:

  • Sun Valley Ski Patrol reported numerous natural and explosives triggered avalanches in closed terrain. The largest slide was triggered by explosives in their expansion terrain. The avalanche ran 1,700 vertical feet, extending further than it's run in over 30 years. 
  • The Soldier Mountain Cat Ski operation reported explosives triggered avalanches in the Soldier Mountains. 
  • Large, natural avalanches crossed Warm Springs Road west of Ketchum.
  • A natural slab avalanche partially blocked Hwy 75 near Galena Summit. 
  • Numerous small avalanches were triggered remotely by riders near Pine, just west of our Soldier & Wood River Valley Zone. 
  • Snowpack collapsing and cracking were widespread. Some collapses traveled to steep slopes, releasing avalanches near Galena Summit and shattering small slopes in the Wood River Valley. 

Snowfall will diminish today, but avalanche conditions will remain very dangerous. Avoid all avalanche terrain. This includes flat slopes in the valley bottom that are threatened from above.

Regions covered