Bulletin d’avalanche

Cooke City

Gallatin NF Avalanche Center
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Danger d’avalanche

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

Points saillants

Danger will increase later in the day as wet avalanches become possible due to sunshine and warm temperatures melting the snow surface. Watch for signs that the snow is becoming wet and unstable, and plan to be off of and out from underneath steep, sunny slopes before the heat of the day. On higher elevation, shady slopes where the snowpack remained drier during recent hot weather it is still possible to trigger large avalanches that break 3-5 feet deep on weak layers that formed in January and February.

Problèmes avalancheux

  • Loose Wet

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

    Wet loose avalanches may be a few inches deep as surface crusts melt through the day. If surface crusts fully melt, wet-loose avalanches could gouge deeper into the sbnowpack and Wet Slabs will also be possible.

  • Persistent Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1–2.5
  • Cornices

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

Avalanche Discussion

This morning the snow surface is refrozen on most slopes, creating generally safe avalanche conditions to start the day. One exception is on higher elevation, shady slopes where the snowpack remained drier during recent hot weather. On Friday skiers near Emigrant Peak triggered a 3-5 foot deep, 1000 foot wide avalanche on a north facing slope (observation). This shows it is still possible to trigger persistent slab avalanches that break on weak snow that formed in January and February.

Danger will increase later in the day as wet avalanches become possible due to sunshine and warm temperatures melting the snow surface. Wet loose avalanches might involve just the top few inches of snow, but could gouge multiple feet deep if surface crusts melt and the snowpack becomes wet and unsupportable. Yesterday in the Northern Madison Range we saw remnants of a few recent large wet loose slides (observation). 

Large wet slab avalanches broke naturally near Big Sky earlier in the week (Cedar Mt. 1, Cedar Mtn. 2), and near Cooke City a couple days ago (Woody Ridge, Town Hill).Wet slab avalanches are less likely today than they have been, but remain possible to trigger on slopes where the snowpack did not refreeze or if surface crusts melt quickly. 

Watch for signs that the snow is becoming wet and unstable, and plan to be off of and out from underneath steep, sunny slopes before the heat of the day. If you sink into wet snow deeper than a few inches, or see rollerballs on the snow surface or fresh natural wet avalanches, it is time to find lower angle or shadier slopes. On shadier slopes, carefully assess the snowpack and terrain for the potential of buried persistent weak layers.

Stay alert for cornices along ridgelines as they have been losing strength from the heat and breaking easily. Give cornices plenty of space if you’re travelling above them on ridgelines and be cautious of slopes below cornices during the heat of the day.

Avalanche danger is MODERATE throughout the forecast area.

Régions couvertes