Avalanche forecast

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
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Avalanche danger

Mon
Alpine
4 · High
Treeline
4 · High
Below
4 · High
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Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Large natural and human-triggered avalanches are very likely. Stay off of and out from beneath all steep slopes. You could trigger slides remotely—from flat terrain below, above, and to the sides of steep slopes.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–2.5

    Expect to trigger 2-4 foot thick slabs in wind-loaded terrain. Avalanches could release naturallly, and cornices could fail and trigger slabs on the slopes below.  Avalanches could be wider than you expect, and very easy to trigger, due to persistent weak layers buried below the recent load from this storm. 

    The size and chance of avalanches will increase as the day progresses. Expect to find slabs near or just below ridgelines, along mid-slope ribs, and on aprons beneath chutes. Cracks shooting out in front of your sled or boards mean you've found a wind slab. 

    (2/1/2025) This natural avalanche released in wind-affected terrain on a N aspect near 9000' in the Frenchman Ck drainage. This avalanche likely failed on weak snow that formed during the January drought.  

    Photo: Allison Kinsler

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    Many steep slopes that are even subtly wind-affected are at their tipping point; avoid all large or consequential avalanche paths that could have any wind-affected snow. In areas sheltered from the wind, persistent slab and loose snow avalanches are possible. The size and chance of avalanches will increase as the day progresses. 

    The 20-40" of recent snowfall is stressing very weak snow that formed during the month long drought, including surface hoar, facets, and facet + crust combinations. These layers exist on many slopes, the worst of which are found at middle and low elevations. 

    A kiss of wind, warm temperatures, or a brief bit of sun is all it takes to consolidate the storm snow into a touchy slab. Although smaller than the thicker wind slabs described above, this problem is tricky. Slabs may release in surprising ways and break wider than expected. You can trigger avalanches remotely—from above, below, or to the sides of steep slopes. It's hard to predict which sheltered slopes are unstable, so build a wide safety margin to handle the uncertainty. 

    Expect heavy sluffing on many steep slopes. Triggered slides of any form may quickly gain mass as they easily entrain the weak facets below, and large sluffs are likely to trigger wider slab avalanches as they move downhill.

    (2/1/2025) Remote skier triggered avalanche in subtly wind-affected terrain in the western Smoky Mtns. As the slab builds and stiffens due to additional snowfall and wind, avalanches will become wider, thicker, and more frequent. 

Avalanche Discussion

Yesterday, Stanley set an all-time record for precipitation on Feb 1. The avalanche equation is simple today: very weak snow from a month long drought + record precipitation + more snow on the way = STAY OUT OF THE WAY.   

Despite yesterday's poor visibility and few observations, there were lots of signs of instability (view complete Observation here): a natural avalanche and a remote triggered avalanche in the western Smokys, extensive cracking and collapsing in the northern Sawtooth Mtns, and collapsing in sheltered, lower elevation terrain near Cape Horn and Trap Ck in the Banner Summit area. Given the steady stream of moderate to heavy snowfall expected to continue, these observations should be viewed as foreshadowing of what's to come. 

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