Bollettino valanghe

South Rockies

Feb 11 – 13, 2021Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 6 years ago

Pericolo valanghe

Sat
Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

The consequences of even small accidents and injuries in this cold weather requires conservative trip plans.

Bonus: Read more about "Managing Moderate" in this new forecaster blog.

Problemi valanghivi

  • Wind Slabs

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

    With plenty of loose snow to redistribute, wind is a major driver of avalanche hazard for now. Use caution around ridges, cornices, and loaded features. In steeper terrain, be cautious of dry-loose avalanches and mindful of sluffing.

    A weak interface may exist in some locations approximately 60 cm down and could reach its threshold with wind stiffened snow, initiating a deeper slab. At this point, this interface seems spotty through the region and hasn't been as reactive as in the Lizard-Flathead region. However, it is something to keep on your radar. 

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

THURSDAY NIGHT - Increasing cloud / light to moderate northeast wind / low near -30

FRIDAY - Partly cloudy / trace of snow possible/ light easterly wind / alpine high temperature a balmy -18

SATURDAY - Increasing cloud / light north east wind / alpine high -19

SUNDAY - Partly cloudy / light southerly wind / highs of -14

Avalanche Summary

Skiers triggered a large (size 2.5) avalanche on a south facing slope in K-Country (forecast region to the north of us) yesterday. Facets over an old sun crust may have played a role. You can read the MIN report here.

Neighbouring forecast regions reported a couple of cornice falls recently, as well as a natural wind slab out of extreme terrain. Ski cuts have been producing small avalanches avalanche in reverse loaded terrain. 

On Friday there was a report of a size 2 explosives triggered wind slab avalanche, as well as a few size 1 human triggered dry loose avalanches. There was also a report of several natural avalanches, potentially up to size 3, a MIN report outlining these can be found here.

Snowpack Summary

Variable winds have redistributed loose snow developing slabs in lee and open features.

A weak interface may exist in some locations approximately 60 cm down and could reach its threshold with wind loading, initiating a deeper slab. At this point, this interface seems spotty through the region and hasn't been as reactive as in the Lizard-Flathead region. However, it is something to keep on your radar! You should dig down and investigate this interface before committing to bigger lines.

In most places 30-60 cm loose snow and soft slab overlies a handful of surfaces: wind affected snow at upper elevations and exposed terrain, softer snow in sheltered areas, and a crust on steep, solar slopes and below 1600-1900 m. 

A solid mid-pack sits above deeply buried decomposing crust and facet layers near the bottom of the snowpack (80-150 cm deep). Though unreactive under the current conditions, steep rocky slopes and shallow snowpacks should still be approached with caution.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Be carefull with sluffing in steep terrain, especially above cliffs and terrain traps.
  • Avoid areas where the snow feels stiff and/or slabby.
  • Carefully evaluate big/extreme terrain features before committing to them, it's not full "go" time yet.

Regioni coperte