Bollettino valanghe

South Coast Inland

Feb 6 – 7, 2020Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 7 years ago

Pericolo valanghe

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

In sintesi

The danger rating is based on the forecast snowfall amounts for the south of the region where 20-35 cm of snow are expected by Thursday evening. Be careful when transitioning into wind affected terrain. Fresh wind slabs will be sensitive to human triggering. 

Problemi valanghivi

  • Storm Slabs

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

    The south of the region is forecast to receive 20-35 cm of snow by Thursday evening whereas up to 10 cm of snow are expected in the north. The new snow will be redistributed by moderate to strong northwest wind and create sensitive wind slabs in lee terrain features in the alpine and at treeline. 

    In the south of the region the precipitation will fall in form of rain below around 1000 m and might form loose wet avalanches.

  • Deep Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    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

Low - Uncertainty is due to difficult to forecast freezing levels. Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Wednesday Night: Snow, flurries in the north of the region and accumulation 10-15 cm in the south, moderate to strong northwest wind, alpine high -5 C. Freezing level 1200 m.

Thursday: Snow, accumulation 5-10 cm in the north of the region and 10-20 cm in the south, moderate to strong northwest wind, alpine high -2 C, freezing level 800 m in the north of the region and 1500 m in the south.

Friday: Flurries, accumulation 5 cm in most parts of the region and 20 cm in the very south, moderate west wind, alpine high -4 C, freezing level 800 m in the north of the region and 1500 m in the south.

Saturday: Mix of sun and cloud, snow, accumulation up to 10 cm, moderate west wind, alpine high -4 C, freezing level 900 m.

Avalanche Summary

There have been no recent reports of avalanche activity. 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 is still concern for deep releases in that part of the region.

Snowpack Summary

New snow develops fresh wind slabs in the alpine and covers recent wind slabs. Extreme southwest wind during the storm last weekend has scoured windward aspects, formed deep loaded pockets in alpine lees and contributed to rapid cornice growth. Below 1800 m, snow overlies a crust and tapers with elevation.

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

  • Watch for avalanche hazard to increase throughout the day.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Regioni coperte