Bulletin d’avalanche

Bitterroot

West Central Montana Avalanche Center
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Danger d’avalanche

Alpin
4 · Fort
Limite forestière
3 · Marqué
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

We’ve issued a special avalanche bulletin for the central and northern Bitterroot and Lolo Pass area due to unexpectedly strong winds, higher than forecast snowfall rates, and increasing avalanche hazard. Dangerous avalanche conditions exist above 6000’. Human triggered avalanches are very likely, and natural avalanches are likely. Travel in avalanche terrain is not recommended. This bulletin is in effect until 10:00 pm on Friday, February 18th. We will issue a standard avalanche forecast on Saturday, February 19th.

Problèmes avalancheux

  • Wind Slabs

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

    Significantly more wind and snow than forecast is impacting the central and northern Bitterroot and Lolo Pass area. Due to the strength of the wind, wind slab has formed not just at ridges but farther down slopes and on multiple aspects. 

    Widespread cracking and wind loading were reported Thursday at Lolo pass. 

    Wind slabs were easily triggered and propagated long distances at Gash Point. 

    Strong winds are forecast to continue through Friday evening, wind slab will continue to build. 

    Travel in avalanche terrain is not recommended. 

    Above 6000’ human triggered avalanches are very likely, and natural avalanches are likely.

     

Avalanche Discussion

The main area of concern, where the avalanche hazard is high at upper elevations, is the central and northern Bitterroot from Lake Como to Hwy 12 and the Lolo pass area. 

Reactive wind slab exists outside of this area, and human triggered wind slab avalanches are likely to occur at upper elevations in the Rattlesnake and Seeley lake zones. 

 

Régions couvertes