Avalanche forecast

Sawtooth & Western Smoky Mtns

Sawtooth Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired last year.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

Highlights

Expect wet snow avalanches in very steep, rocky terrain receiving direct sun. You could trigger a large avalanche where the wind has formed drifts and stiffened the snow surface. Cornices are large and may be unstable—give them a wide berth.

Avalanche problems

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2

    Loose snow avalanches are likely on very steep, rocky slopes receiving direct sun. These slides often initiate near the base of trees and rocks, gathering snow and growing in size as they move downhill. Rollerballs, or pinwheels, signify that the snow is heating up, and wet avalanches may soon follow. 

    While most will start small, they may will grow large and dangerous or push you into unwanted terrain. Some slides have the potential to flank out into wider wet slab avalanches. Even small slides are consequential above terrain traps such as gullies, creeks, and thick timber. Plan your day to avoid lingering under steep, sunny slopes when the sun is out.

    (2/26/2025) Wet snow avalanches in the Marshall Lake Basin. Sawtooth Mountains. 

  • Wind Slabs

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

    Recent snowfall and strong SW and W wind built 1-2' thick slabs in areas exposed to the wind. As you climb into windier upper elevations, these slabs will be thicker and found in more terrain. On some slopes, slabs formed on crusts and/or weak snow, and avalanches could be easy to trigger or break wider than you expect.

    Slabs often form near ridgelines, along steep mid-slope gullies, or on aprons below steep cliffs. You can reduce your chances of triggering a wind slab by avoiding slopes with obvious signs of wind-loading, such as new cornice growth and large dunes or pillows of wind-blown snow. Some slabs may not be obvious from a distance. A sudden stiffening of the snow you're traveling through, or cracks shooting from your skis or sled can indicate an unstable slab.

    Additional Discussion - Cornices: Cornices are large and may be unstable. Tuesday, we easily triggered a 200' wide and up to 8' thick section of freshly formed cornice. Warming temperatures may cause overhanging cornices to sag and fail. Limit time beneath these features and give them a wide berth when traveling along ridges. 

    (2/24/2025) Large slab avalanches in the Meadow drainage of the Sawtooths. Photo: Zachary Miller

Avalanche Discussion

It's day 2 in a string of warm, sunny days. Last night, temperature inversions kept upper elevations warmer than lower elevations and will be ahead of the curve today as surfaces soften. Today's sunshine will have to overcome crusts at the surface, but alpine temperatures in the 40s F and strong sunshine will eventually turn the surface to mush. This wet snow may slide far and fast on crusts beneath the surface. This zone has an abundance of craggy, sheltered cirques, perfect for producing large wet avalanches. Steep, sunny slopes are riddled with crust/facet layers. As meltwater moves deeper into the snowpack, we may see large, destructive wet slab avalanches.

The timing of wet snow avalanche problems varies greatly with location, aspect, and elevation and is nearly impossible to predict. Build this uncertainty into your travel plans and limit time on or under steep, sun-drenched slopes.

Regions covered