Bollettino valanghe

South Coast

Mar 2 – 3, 2014Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 13 years ago

Pericolo valanghe

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

In sintesi

New snow and wind are developing a new storm slab that may not bond well to the old surface of crusts and facetted crystals. Check out the forecaster blog for more information on the persistent weak layer.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–5
    Human triggering with long fracture propagation resulting in very large avalanches continues to be a concern. North aspects in the alpine are the most likely slopes to have a well preserved weak layer with a cohesive slab above.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–3
    Forecast new snow and wind are expected to develop a new storm slab that may not bond well to the old surfaces.

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Overnight and Monday: Light snow overnight combined with moderate Southwest winds and freezing levels around 500 metres. Snow becoming moderate to heavy in the morning bringing 10-15 cm combined with strong Southwest winds during the day. The freezing level is expected to climb up to about 1200 metres.Tuesday: Snow ending by morning as the freezing level slides back down to about 500 metres. Expect strong Southwest winds.Wednesday: The next pulse of moisture should start during the day. Expect strong Southwest winds combined with the snow.

Avalanche Summary

No new avalanche activity reported since the cold arctic air moved into the region. Forecast new snow and strong winds may develop a new storm slab by morning.

Snowpack Summary

Cold dry snow has started to bury the melt-freeze crusts and surface facets that developed over the past few cold days. Melt-freeze crusts developed on all aspects at lower elevations, and on all but Northerly aspects in the alpine. Last weeks very warm temperatures and periods of very strong solar radiation caused a great deal of settlement in the old storm slab above the early February weak layer. The February weak layer of crusts and facets has been reported to be rounding and bonding in areas where the old storm slab is 200 cm or deeper ( there is between 2-3 metres of snow above the weak layer in the Coquihalla area). Shallow snow pack areas where the old storm slab is closer to a metre or less continue to give sudden planar shears in snow profile tests ( there is about 60-80 cm above the weak layer in the Duffey Lake area). North aspects in the alpine may have had enough warming to settle the storm snow into a cohesive slab, but not enough to improve the weak layer bond. Big un-supported alpine North aspects are the most likely place to find a well preserved deeply buried February weak layer that may continue to allow for long propagations resulting in very large avalanches.

Regioni coperte