Bollettino valanghe

Kootenay Boundary

Mar 17 – 18, 2022Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 5 years ago

Pericolo valanghe

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

In sintesi

Cautious route-finding is recommended right now due to uncertainty about buried weak layers, especially in the eastern parts of the region where there is potential for large avalanches.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    30 to 50 cm of recent snow has potential to form a persistent slab above weak layers. There have been reports of a poor bond to underlying sun crust layers on south slopes and surface hoar crystals on north slopes, especially north and south of Nelson in the Selkirk Range.

    At this point we are uncertain about how long this problem will take to heal and suggest a more conservative approach to terrain to handle this uncertainty.

Confidence

Moderate - Uncertainty is due to the complexity of the snowpack’s structure.

Weather Forecast

THURSDAY NIGHT: Cloudy with scattered flurries bringing up to 5 cm of new snow, light wind from the southwest, treeline temperatures drop to -5 with freezing level around 1200 m.

FRIDAY: Mostly cloudy with some light flurries bringing trace amounts of snow, moderate wind from the southwest, treeline temperatures around -3 C with freezing level around 1500 m.

SATURDAY: Mostly cloudy with flurries starting midday brining up to 5 cm of snow, moderate wind from the southwest, treeline temperatures around -3 C with freezing level around 1500 m.

SUNDAY: Flurries continue overnight with 5 to 10 cm of new snow by the morning then sunny breaks in the afternoon, light wind from the west, treeline temperatures around -5 C with freezing level around 1300 m.

Avalanche Summary

Avalanche activity has declined since a natural cycle occurred during Tuesday's storm. The cycle involved many large storm slab avalanche in the top 20 to 40 cm of snow (size 2). On Wednesday, activity was limited to a few natural slab and loose avalanches triggered by warming on south-facing slopes (size 1 to 2).

There have been some notable human-triggered avalanches north of Nelson the past few days in the South Columbia region (read more in this blog). These have been larger storm slabs above weak layers, and we are uncertain whether these are signs of a developing persistent slab avalanche problem that could begin impacting northern and eastern parts of the Kootenay Boundary region as well.

Snowpack Summary

30 to 50 cm of snow from the past week is settling, and there is uncertainty about how well it will bond to underlying layers. In the Selkirks, especially north of Nelson, it appears this snow could be bonding poorly to underlying crust and surface hoar layers. In the Monashees, it appears this snow has formed a stronger bond to underlying crusts. There are several other crust layers found 30 to 70 cm deep, and it appears the snow is mostly well bonded to these crusts.

Terrain and Travel

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Approach steep, open and/or sparsely treed slopes cautiously.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Investigate the bond of the recent snow before committing to your line.

Regioni coperte