Bulletin d’avalanche

East Cabinet Mountains

Idaho Panhandle Avalanche Center
Voir sur la carte

Danger d’avalanche

Fri
Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
3 · Marqué
Open full map
Périmé — ce bulletin a expiré 5 months ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Violent winds and heavy snowfall have created very dangerous conditions in the mountains. You can easily trigger an avalanche large enough to bury, injure, or kill you and some will release spontaneously. Avoid travel in avalanche terrain today.

Problèmes avalancheux

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–2.5

    All the classic, dangerous ingredients exist today to make triggering an avalanche very easy. An inverted slab (harder layers over softer layers) sits directly on top of a smooth, very firm crust. This slippery interface will help enhance sensitivity of these fresh slabs and they are expected to be touchy even where slab depths are less than a foot deep. The most dangerous slopes, and where avalanches are likely to grow larger in size, are where hurricane force winds drifted the new snow into deeper and stiffer slabs. These will be found below ridges, on side walls of gullies, and potentially lower down on slopes and at lower elevations with how strong the winds have been.

    If you choose to travel in the mountains today, very conservative terrain choices are imperative. If you cannot see the terrain above you, consider another spot to recreate as weird weather often breeds weird, unexpected avalanche behavior.

    (3/11/2026)

    Annotated photo of slab hardness and test results in a wind-drifted area on a north-facing slope around 5,700 feet. West Cabinet Mountains. March 11, 2026.

    Photo: Chris Bilbrey

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    2–3

    A 3 to 5-foot-thick cohesive slab overlies two buried surface hoar layers. One got buried at the end of January (1/28) and the other in mid-February around Valentine’s Day (2/14). The slab above has stiffened and settled due to wind, warmer temperatures, and natural settlement. As the slab has strengthened, the likelihood of human-triggered avalanches has decreased, and natural avalanches have become unlikely. Although the sensitivity of these weak layers was trending in the right direction prior to the most recent storm, the rapid weight added in the last 48-hours might be enough to reinvigorate some instability. The overlying slab has hardened and thickened substantially over time and now the destructive potential and inherent consequences remain significant if one of these persistent weak layers is woken up and an avalanche occurs. 

    Snowpack feedback and signs of instability in the form of audible collapses, shooting cracks, or worrisome test results are becoming harder to come by, and there will likely be little to no warning before you trigger a large avalanche. Shaded, more wind-protected slopes that favor the northern half of the compass are the most likely places where looming persistent weak layers will be intact. Areas with a thinner or softer overlying slab may act as trigger points and the initial fracture could expand to places where the slab is deeper and more destructive. Navigate around slab margins, rocky slopes, and steep convex rolls where snow depths are likely shallower if traveling through avalanche terrain.

    (3/9/2026)

    Large surface hoar up to 8mm in size is visible to the naked eye at the January 28th interface. This layer is found 3 to 5 feet below the surface and was exposed here after the overlying slab failed and slid downslope during a propagation saw test.

    Photo: Jackson George

Avalanche Discussion

Today is not a day to venture into the mountains without a clearly defined objective that avoids avalanche terrain. The term “avalanche terrain” may expand beyond the typical terrain we commonly associate with avalanche hazards. This is due to the hurricane force winds and gusts potentially blowing the new snow lower down on slopes and into elevations well away from ridgelines and common start zones. In some instances, the violent winds may have blown all the recent snow into the Dakota’s exposing the old hard crust. This would lend to dangerous slide-for-life conditions in steeper terrain that is another hazard in and of itself.

As long as snowfall continues, even if winds relax as forecast, an inverted Storm Slab (harder over softer) has already been formed and will continue to thicken. This slab layering makes the new snow more sensitive than if it accumulated right-side-up (softer or harder). These slab properties combined with sitting directly on top of a widespread and planar sliding surface throws the common idea out the window that slabs need to be around 6 inches or more to produce a larger slide. The crust below will help slides break wider and run faster downslope increasing the chance to catch you or your group off guard.

As often said during times like this, if stability is in question then terrain is always the number one answer. Working on a house project or going bowling might be the best course of action till things settle down and conditions become more pleasant overall.

---

IPAC is now on the Avy app! View, submit, and share observations on the go using the AvyApp. Your backcountry observations are critical for building our avalanche forecasts. Avy provides a centralized location for core trip planning, and you can view streamlined, up-to-date avalanche and weather forecasts for your selected zone, using offline caching. Download Avy today - App Store and Google Play.

Régions couvertes