Avalanche forecast

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Warmer temperatures and new, heavier snow falling on existing lighter snow will create an upside-down slab. These slabs will be most reactive just downwind of ridgelines and gullies at upper elevations, where snow totals are higher, and the wind has created stiffer and thicker slabs. Triggering an avalanche in the storm snow has the potential to step down to deeper buried weak layers, which could produce an avalanche that would be large enough to bury, injure, or kill a person. Adjust travel plans to low-angle terrain if you feel a firm over soft slab and experience shooting cracks on the surface.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2

    New snow and winds are building slabs over weak, sugary faceted snow. As slab depths increase during the day and beyond, the sensitivity of these weaker grains will also increase. Heightened evaluations become a broader concern as you approach upper elevation slopes where a deeper snowpack exists, and more places harbor an old, hard refrozen crust in the lower snowpack. Use extra caution in these specific areas, look for cracking on the snow surface, and build in a wider margin of safety as early-season uncertainty exists.

  • Storm Slabs

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

    A strong winter storm moved into the Idaho Panhandle yesterday, delivering 2–8 inches of dense new snow by this morning. Snow depths are variable across elevations and between forecast zones. The Silver Valley received the greatest impact, with higher snow totals, warmer temperatures, and stronger winds.

    Snowpack instability is possible anywhere a cohesive slab has formed over a softer, weaker layer. The likelihood of triggering a slab increases in wind-loaded terrain or in areas that picked up more than 6 inches of new snow. Overnight ridgeline winds in the Silver Valley and Southern Selkirks reached 20–30 mph, more than enough to transport snow and load starting zones. It remains wise to actively look for signs of instability anywhere you find 8 inches or more of new snow.

    Be alert for firm snow resting over softer layers. Quick assessments, such as hand pits or small, safe test slopes, can provide valuable information about new-snow bonding. Shooting cracks, recent avalanches, or other obvious signs of instability should be treated as red flags. With additional snowfall expected today, avalanche danger will continue to rise through the day

Avalanche Discussion

Yesterday’s storm delivered periods of moderate to heavy snowfall. The Silver Valley-Bitterroots received the brunt of the wind, with gusts approaching 40mph. Temperatures rose throughout the day, causing the snowline to fluctuate.

More dense and heavy snow is on tap for today. The southern end of the forecast region is again favored with the higher snowfall amounts. The area around Lookout Pass could see 10” of new snow by tomorrow, and a winter storm warning is currently in effect for that area. With today’s forecasted temperatures reaching into the low 30s°F, new snow will be dense and wet, creating an upside-down snowpack, where a denser slab rests on lighter, weaker snow.

Although we have yet to observe propagation in our stability tests, the current snowpack structure is weak and showing signs of instability. An array of weak layers exists within the snowpack, including facets sitting on a stout crust buried 1 to 2 feet deep, and weaker layers within the newer snow. Adding more wet, heavy snow on top of this weak structure will push these worrisome layers closer and closer to failure. The additional weight of a skier or snowmobiler may be the final nudge to tip things over the edge. The presence of wind strong enough to transport snow will only increase the slab stiffness and sensitivity at upper elevations.

Due to the warming temperatures, new snow may transition to wet snow at mid and lower elevations. Observing pinballs that gain in size or seeing sluffs that continue to entrain more snow as it moves downhill are red flags and suggest that it’s time to move away from steep slopes. Terrain features such as gullies and chutes will be the most likely places to see this transition.

Despite the fresh accumulation, coverage remains thin, particularly at lower elevations and on southern aspects. Early-season hazards—rocks, stumps, downed trees—are lurking just beneath the surface: invisible enough to catch you off guard, shallow enough to abruptly end your day if you’re skiing or riding fast. Stay vigilant, monitor changing conditions, and be ready to adjust your plans when venturing into the mountains.

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