Bulletin d’avalanche

Silver Valley & Bitterroot Mountains

Idaho Panhandle Avalanche Center
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Danger d’avalanche

Sat
Alpin
2 · Modéré
Limite forestière
2 · Modéré
Sous la limite
2 · Modéré
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Périmé — ce bulletin a expiré 5 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Temperatures have remained at or above freezing for much of the forecast area since the rain/wintery mix precipitation on Tuesday. Lots of roller balls and small loose wet slides are indications that avalanche danger exists at lower and mid elevations. Stay out of terrain traps and use extreme caution crossing avalanchable terrain. Stubborn wind slabs may persist at upper elevations in isolated locations.

Problèmes avalancheux

  • Loose Wet

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2

    At low to mid elevations natural and triggered wet slab avalanches are possible today. Moisture penetrated and has lubricated the upper 50cm of the snowpack. On south facing road cuts at low elevations small wet avalanches went to ground. As temperatures rise throughout the day likely hood of triggering a loose wet slide will increase. Dense wet snow slides that entrain into terrain traps, or on steep continuous slopes, are very dangerous and hard to escape.

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Unlikely
    Taille
    1–1.5

    Stubborn wind slabs may still be present in isolated locations at mid to upper elevations. Low winds, mild temperatures, and moisture have diminished this problem. However, we continue to find reactive layers in the upper snowpack on wind loaded terrain during Compression Tests that are worth keeping an eye on. Although they were not reactive in our Extended Column Tests, these are spatially variable and could be triggered in isolated locations.

Avalanche Discussion

Yesterday we toured up to Willow Peak in spring-like conditions.

We found a crust of varying thickness and strength on all aspects at all elevations.. The crust was robust and 5-10cm thick over saturated snow at lower and mid elevations, but thin and fragile over dry snow at upper elevations. However, sun exposed slopes became mash potatoes by mid-afternoon. Lots of rollerballs and evidence of small loose wet slides on low to mid elevations.

The avalanche danger will continue to trend down over the weekend if mild temperatures, overcast skys, and low winds continue as forecasted. A small amount of light snow may blanket the crusts above 4000ft. Between the crusts and mashed potatoes, the riding and sliding conditions will be variable. Continue to exercise caution and good judgment in choosing slopes and terrain.

Régions couvertes