Bollettino valanghe

South Coast Inland

Feb 26 – 27, 2024Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 3 years ago

Pericolo valanghe

Wed
Thu
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
1 · Debole

In sintesi

Dangerous avalanche conditions exist where new snow and wind continue to add load above buried weak layers.

Uncertainty is best managed through conservative terrain choices at this time.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Recent snow and strong southwest winds have built fresh wind slabs in lee terrain features. Wind slabs are most reactive where they overlie a crust.

  • Persistent Slabs

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

    Recent observations show that a problematic weak layer from early February, of facets overlying a crust, is becoming increasingly triggerable. This layer was the culprit of recent human-triggered avalanches in the region.

Snowpack Summary

5 to 15 cm of storm snow and strong westerly winds have created fresh wind slabs in open areas at treeline and above. Recent snow overlies a variety of surfaces including a crust on south facing slopes, wind affected surfaces in open areas and faceted surfaces in sheltered areas.

Roughly 40 to 60 cm down is a widespread crust with a weak layer of facets or isolated surface hoar above this crust. This problematic layering remains a concern with recent avalanche activity and snowpack tests showing reactivity. Human triggering avalanches on this layer remains possible.

Confidence

Moderate

Avalanche Summary

On Sunday, operators reported signs of instability such as shooting cracks and snow pillows failing on the persistent weak layer. Poor visibility means observations at higher elevations were limited.

On Saturday, skier triggered wind slab avalanches were reported to size 1.5. A skier accidental persistent slab avalanche was reported on a west aspect at 1900 m. The avalanche happened on a steep treeline feature and failed on surface hoar above the February 1 crust.

Weather Summary

Sunday Night

Mainly cloudy with 0 to 2 cm of snow. 30 to 40 km/h west ridgetop wind. Treeline temperature -12 °C. Freezing levels drop to valley bottom.

Monday

A mix of sun and cloud with 1 to 2 cm of snow. 20 to 30 km/h northwest ridgetop wind. Treeline temperature -13 °C. Freezing levels remain at valley bottom.

Tuesday

Increasing clouds. 20 to 40 km/h northwest ridgetop wind. Treeline temperature -15 °C. Freezing levels remain at valley bottom.

Wednesday

Cloudy with 5 to 15 cm of snow. 50 to 80 km/h southwest ridgetop wind. Treeline temperature rises to -3 °C. Freezing level rises to 1500 m throughout the day.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid freshly wind loaded terrain features.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Regioni coperte