Bollettino valanghe

Kootenay Boundary

Mar 18 – 19, 2025Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 2 years ago

Pericolo valanghe

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

In sintesi

Numerous large rider triggered avalanches continue to be reported in this region.

Triggering is most likely at treeline and above on wind-loaded slopes.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Several persistent weak layers exist in the upper metre of the snowpack. Small avalanches in motion may trigger these deeper layers creating very large and destructive avalanches.

  • Storm Slabs

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

    Up to 60 cm of recent snow has formed reactive storm slabs. These slabs will be most reactive on wind-loaded slopes and on sunny slopes during periods of strong solar radiation.

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1–1.5

    Wet loose avalanches will become very likely when the sun comes out. Avoid overhead hazard from steep sunny slopes when the solar radiation is strong.

Confidence

Moderate

Avalanche Summary

On Monday, numerous skier triggered storm slab avalanches up to size 2 were reported primarily at treeline and above on a variety of aspects. Here's one example.

A snowcat triggered a size 2.5 persistent slab avalanche on the early March Surface hoar layer on a east aspect at treeline. The avalanche stepped-down 90 cm to the late January surface hoar layer.

A cornice fall also triggered a storm slab which triggered a size 2.5 persistent slab on the early March layer.

Snowpack Summary

40 to 65 cm of recent snow and southwest winds formed slabs reactive to human triggers.

Concern remains for triggering persistent slab avalanches. These layers include:

  • Facets/surface hoar/crust from early March buried 40-70 cm.

  • Facets/surface hoar/crust from mid-February buried 60-100 cm

  • Facets/surface hoar/crust from late January buried 100-160 cm.

The lower snowpack is well settled and strong.

Weather Summary

Tuesday Night

Clear skies, 10 to 20 km/h southwest ridgetop winds, treeline temperature -8 °C, freezing level valley bottom.

Wednesday

Mix of sun and cloud, 30 to 40 km/h south ridgetop winds, treeline temperature -5 °C, freezing level 1400 m.

Thursday

Cloudy with flurries, 5-10 cm snow, 20 to 30 km/h southwest ridgetop winds, treeline temperature -4 °C, freezing level 1500 m.

Friday

Snow, 10-20 cm, 30 to 40 km/h southwest ridgetop winds, treeline temperature -4 °C, freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.
  • Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
  • Use small, low consequence slopes to test the bond of the new snow.
  • Be aware of the potential for larger than expected storm slabs due to buried surface hoar.
  • Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.

Regioni coperte