Bulletin d’avalanche

Continental

Valdez Avalanche Center
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Danger d’avalanche

Alpin
4 · Fort
Limite forestière
4 · Fort
Sous la limite
4 · Fort
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Périmé — ce bulletin a expiré 3 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

The avalanche hazard is HIGH at all elevations.  Significant snowfall alongside rising temperatures overnight has created widespread areas of unstable snow. Natural avalanches are likely and human triggered avalanches are very likely.  Travel in avalanche terrain is not recommended.

 

Problèmes avalancheux

  • Glide Cracks

    • Toutes altitudes
    Probabilité
    Unlikely
    Taille
    2.5–3

     Glide avalanches are a strange beast that act differntly than other avalanche problems.  Full depth failure occurs independent of snowpack stability.  Or in other words, they can release even when a stable snowpack is in place.

    Since it is not possible to time their sensitivity the only way to mitigate this hazard is by avoidance.  First identify where glide cracks exist and avoid spending time beneath them.  Glide cracks are easy to identify.  They look like crevasses, but exist in non glaciated terrain.

    These do not produce small avalanches,  but rather failure will include the entire snowpack.  

    Glide release on Town mountain

    Photo: Rich Lofton

  • Storm Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Very Likely
    Taille
    1.5–3

    2-3 feet of snow has accumulated in our forecast zone over the last 36 hours along with rising temperatures overnight.  This has created widespread areas of unstable snow.  Travel in avalanche terrain is not recommended.  Stay away from avalanche runouts as natural slides could run into valley floors.  

Avalanche Discussion

Our upper snowpack is undergoing a major change.  Just like people snow does not like big changes to happen quickly.  When the snowpack is under stress as it is currently, avalanches are the result.

We now have all three ingredients of the avalanche recipe.  First we have a bed surface created by the previous week of strong north winds that made a very hard/slick surface. Second we have a weak layer which is the very dry snow that has initially fallen during the storm.  Third and most importantly we have formed a slab as temperatures warmed overnight.  Continued snowfall at higher temperatures will likely overload the significant amount of dry snow that fell yesterday.  

Natural avalanches are likely and human triggered avalanches 2-4 feet in depth are very likely.  Travel in avalanche terrain is not recommended.

Step down avalanches are not anticipated as the strength of the wind board at the new/old interface and structure below has been obseved to be strong.  This will be a good test.

Glide cracks have been observed in all three forecast zones.  Avoid travelling beneath these as full depth avalanches can release unexpectedly.

Valdez season snowfall: 188+inches

Valdez January snowfall: 44+  inches

Valdez height of snowpack: 67+ inches

Thompson Pass snowfall data is currently unavailable

46 mile height of snowpack: ~80 inches

Régions couvertes