Bollettino valanghe

Lutak

Haines Avalanche Center
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Pericolo valanghe

Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Non aggiornato — questo bollettino è scaduto 3 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Recent snowfall buried a widespread crust that formed at all elevations. Be on the lookout for strong over weak layering around this crust and look for other clues of slab formation, such as active wind loading, recent avalanches, shooting cracks, or any whumphing/collapsing. Avoid terrain features with a cohesive slab and use good travel techniques like not grouping under slopes and traveling one at a time.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2.5

    15-20" of fresh snow from Wednesday night to Thursday morning could have slab properties and fail.  Signs of active wind loading, recent avalanches, shooting cracks, or any whumpfing/collapsing are helpful in determining a developing slab within the new snow. Snow is also readily available for transport if the incoming N-NW winds pick up. 

    Last week, above freezing temperatures across all elevations of the Lutak zone caused the formation of a thick, widespread "end of year" (EOY) melt freeze crust. With recent snowfall, the EOY crust could act as a bed surface as new snowfall layers on top and triggering is still possible.Strength of crust is variable and elevation dependent, due to duration and intensity of the EOY event.  

    Use caution around wind effected snow in exposed areas along ridgelines and in crossloaded gullies.

Avalanche Discussion

A slab avalanche that fails on weak faceted snow surrounding the EOY crust is still possible and these weak forms need to be monitored and assessed. Cold temperatures will slow healing and drive faceting at the surface and around weak layers above and below crusts layers.

Also, from earlier this season, and now more than a meter deep, a few melt-freeze layers are present throughout the snowpack at all elevations and aspects. These layers have mostly been found to be healing but could fail and produce an unlikely though larger avalanche. So far this season, our overall warmer and wetter temperature regime has helped slow the development of persistent weak layers (PWL's) in the snowpack. These deeper layers continue needing reassessment, especially as temperature regimes change with colder, high pressure trends in the long term forecast. 

The people you go out with, the way you communicate, and the way you practice risk reduction as a team throughout the day is equally important as the conditions.

Help us gather information about weather, snowpack, and avalanche activity by reading and submitting field observations. Useful observations can be anonymous and include: 

  • Natural or human-triggered avalanche activity
  • Signs of instability: Cracking, collapsing, or whumphing
  • Red Flag Weather: Precipitation, wind loading, warming temperatures and rain-on-snow
  • Surface hoar growth, snow depth, persistent weak layers, etc
  • Snow stability tests, or pit result and location, elevation, aspect, etc 

Were you caught, carried, injured or buried in a slide? We are all human and can benefit from lessons learned, please report incidents to Haines Avalanche Center staff confidentially.

Regioni coperte