Bollettino valanghe

South Coast Inland

Feb 9 – 10, 2020Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 7 years ago

Pericolo valanghe

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

In sintesi

Friday's storm delivered 20-30 cm in the south of the region and 10-15 cm in the north with changing wind direction from southwest to north. Wind slabs were created on all aspects and might still be sensitive to human triggers especially when hit by the sun. 

Problemi valanghivi

  • Storm Slabs

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

    Friday's storm delivered 20-30 cm in the south of the region and 10-15 cm in the north. The new snow sits on a variety of surface and it is uncertain how well the new snow bonds to the old snow surface. 

    The wind changed direction during the storm from southwest to northerly and created wind slabs on all aspects at treeline and in the alpine. These wind slabs might still be sensitive to human triggers especially when exposed to the sun. 

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely
    Dimensione
    2.5–4

    Although the likelihood of triggering a deep persistent slab avalanche has reduced, doing so would result in a large and destructive avalanche. These layers do not pose an avalanche problem in the south half of the region.

Confidence

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

Weather Forecast

Saturday Night: Clear, light to moderate northwest wind, alpine high -12 C, freezing level at valley bottom.

Sunday: Mix of sun and cloud, light to moderate northwest wind, alpine high -8 C, freezing level 1000 m.

Monday: Mostly sunny, light to moderate northwest wind, alpine high -5 C, freezing level 1500 m.

Tuesday: Mostly cloudy, light to moderate southwest wind, alpine high -5 C, freezing level 1000 m.

Avalanche Summary

No new avalanches were reported on Thursday and Friday.

On Wednesday numerous small (size 1) natural slab avalanches were observed below treeline which released within the recent storm snow and were very soft. Several small (size 1) and one large (size 2) loose dry avalanche were reported. 

The deep persistent slab avalanche activity observed during last weekend's storm in the northern portion of the region seems to have tapered off. Although the likelihood of triggering has reduced there is still concern for deep releases in that part of the region.

Snowpack Summary

Friday's storm delivered 20-30 cm in the south of the region and 10-15 cm in the north. Strong southerly wind during the storm shifted to northerly wind and created wind slabs on all aspects. The snow surface is wind affected at treeline and in the alpine. The recent storm snow sits on a rain crust below 1900 m.

In the north part of the region (ie. Goldbridge/Duffey/Hurley), a few deep instabilities exist in the snowpack, including a weak basal facet crust complex. This has been the failure plane in ongoing reports of very large, deep persistent avalanches.

The south of the region, including the Coquihalla and Manning areas, currently have no concerns about deeply buried weak layers.

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Be especially cautious as you transition into wind affected terrain.
  • Be alert to conditions that change with elevation.

Regioni coperte