Avalanche Forecast

Issued: Mar 1st, 2012 9:22AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Wind Slabs and Persistent 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: An approaching warm front from the NW will bring light snow amounts near 5 cm. Ridgetop winds moderate from the SW. Treeline temperature near -5. Freezing levels could rise to 900m. Saturday: Snow amounts up to 10 cm. Ridgetop winds moderate-strong from the SW. Treeline temperatures near -2. Freezing levels rising to 12-1500 m. Sunday: Snow amounts up to 10 cm. Ridgetop winds moderate from the SW. Freezing levels near 1000 m.

Avalanche Summary

A a rider triggered size 2 avalanche occurred on the Duffy. The sliding layer being the aforementioned preserved stellaras that exist down 30 cm. The Coquihalla saw a brief natural solar induced cycle up to size 2, all slides stopping mid-track. As reports of natural activity have started to taper off, rider triggers are likely and still occurring. 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. With forecast snow, wind and rising freezing levels, you can expect to see the danger ratings elevate over the weekend. 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

Changing winds have created pockets of wind slab exist on multiple aspects in upper elevations. Thin sun crusts are seen on solar aspects. Dribs and drabs of new snow fell over the week, while the main bulk of the storm snow fell last weekend. In both areas, down 30-40 cm is a preserved stellar interface that is providing easy, sudden planar test results, and a rutschblock score of 2 (whole block failing). The mid February interface (crusts at lower elevations, and buried surface hoar in sheltered locations) is down approximately 60 cm below the surface. The weak interfaces have created tricky snowpack conditions. Below this the lower snowpack is well bonded and strong.

Problems

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.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
Forecast snow through the weekend may add to the current storm snow instabilities; especially in areas that overlie preserved stellars, facets, buried surface hoar and crusts. Avalanches sliding on this layer may be large and destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 6

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