Avalanche Forecast

Issued: Feb 28th, 2012 9:30AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Persistent Slabs and Wind Slabs.

Avalanche Canada swerner, Avalanche Canada

The snowpack is tricky to predict at the moment. Backcountry travel requires local knowledge, extensive experience and training. Please read the new Forecaster's Blog Post.

Summary

Confidence

Good

Weather Forecast

Wednesday: Flurries throughout the day, snow amounts 5-10cm. Ridgetop winds moderate from the South. Treeline temperatures near -12. Thursday: A mix of sun and clouds through the day, staying dry and cool. Solar radiation in effect during the afternoon. Ridgetop winds light from the SW. Treeline temperatures near -8. Friday: A strong westerly flow brings cloudy skies and light snow amounts. Ridgetop winds moderate-strong from the West. Treeline temperatures near -6. Freezing levels remain at valley bottom through the forecast period.

Avalanche Summary

Natural activity up to size 2.5 has been reported on S-SW aspects in exposed locations at treeline and above. This is due to northerly winds, causing reverse loading, and wind slab problems. Where it exists, the mid February interface continues to be reactive up to size 2.5; especially within treeline elevation bands. I suspect natural activity will taper off, but rider triggers are likely. The snowpack is very tricky at the moment. Backcountry travel requires local knowledge, extensive experience and training. The obvious clues that show snowpack instability may not be there. You need to dig deep, do your detective work and make good decisions. Don't let the sunny skies, and other tracks fool you, and/ or lead you into a situation you won't be able to deal with. Visit the link below to check out the recent incidents in your area: http://www.avalanche.ca/cac/library/incident-report-database/view

Snowpack Summary

Recent storm snow totals in the Duffey Lakes is 15-25cm while in the Coquihalla summit area its 30-40cm. Northerly winds have created reverse loading, and new wind slab problems on S-SW aspects. In both areas, the mid February interface is down approximately 60 cm below the surface. This includes crusts at lower elevations, and buried surface hoar in protected areas. This layer has been reactive to natural and rider triggers, especially around treeline elevations. Below this the lower snowpack is well bonded and strong. Solar radiation may be a factor on Thursday afternoon, avoid sunny slopes if you see obvious signs of snowpack deterioration ( natural avalanche activity, snowballing, moist and/or surface snow)

Problems

Persistent Slabs

An icon showing Persistent Slabs
Storm slabs linger and remain reactive where they exist in combination with buried surface hoar; especially in sheltered treeline locations. Avalanches sliding on this layer may be large and destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Wind Slabs

An icon showing Wind Slabs
Changing winds have created more widespread wind slabs. Cracking, whumphing and/or hollow drum like sounds beneath you are all indicators.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Feb 29th, 2012 8:00AM

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