Avalanche Forecast

Issued: Mar 1st, 2012 9:13AM

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

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Friday: The approaching warm front brings light snowfall amounts throughout the day, accumulations near 10 cm. Ridgetop winds 30-50km/hr from the West. Treeline temperatures -8. Freezing levels could rise to 600 m. Saturday: Snow amounts up to 10 cm. Ridgetop winds moderate from the West. Treeline temperatures -8. Freezing levels valley bottom. Sunday: Significant change in weather. Precipitation heavy through the day, winds moderate from the SW, and freezing levels 700m.

Avalanche Summary

Recent avalanche activity consists of new, low density snow sluffing from steep terrain up to size 1.5. On Monday a sled triggered size 2 avalanche occurred in the Telkwa Pass area. Reports indicate the elevation was near 1350 m, on a South aspect. The crown depth was 45 cm, 100 m wide, and ran 100 m down slope. One member of the party was buried up to his chest, but sustained no injuries. A skier triggered size 2 avalanche, also occurred on Monday in the Smithers/Hankin area. The report indicates the slope was triggered while skiing over a convex feature in an open area within the trees. The skier went for a 20 m ride, and was buried chest deep. No injuries reported. 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. Rider triggered avalanches are likely. Check out this link to view the incident report database: http://www.avalanche.ca/cac/library/incident-report-database/view

Snowpack Summary

Due to changing winds, wind slabs can be found on N-NE aspects and S-SW aspects in the alpine on exposed slopes at treeline. Currently, up to 60cm of snow sits over the mid February interface. This interface is variable, it consists of a strong melt freeze crust below 1000m, above 1000 m exists facets, surface hoar (in more sheltered areas), sun crust or wind press. The surface hoar is not widespread but is responsible for much of the larger avalanches that occurred earlier this week. This layer should be on your radar, as it may be susceptible to rider triggers. With forecast wind, snow and rising freezing levels this layer may show its wrath again. It's a good time to play conservatively. Below this, the mid and lower snowpack is well settled and strong.

Problems

Persistent Slabs

An icon showing Persistent Slabs
New storm slabs will develop with forecast snow. This adds to the current storm slab instabilities; especially in areas where they overlie buried crusts, facetted snow, and/or sheltered areas with buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 6

Wind Slabs

An icon showing Wind Slabs
Increasing winds have formed wind slabs on lee slopes and terrain features. Cracking, whumphing and/or hollow drum like sounds beneath you are all indicators.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Valid until: Mar 2nd, 2012 8:00AM