Avalanche Forecast

Issued: Dec 24th, 2011 9:21AM

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

Avalanche Canada pgoddard, Avalanche Canada

Click on the 'Forecaster's Blog' link below for more discussion on how to travel safely under the current conditions.

Summary

Confidence

Fair - Due to variable weather conditionsfor the entire period

Weather Forecast

Sunday: Generally light snowfall with a pulse of moderate snowfall expected in the afternoon. The freezing level will rise to 800m by afternoon. Strong south-westerly winds at ridge top.Monday/Tuesday: Further light precipitation with moderate-strong south-westerly winds. The freezing level should slowly rise in the early part of the week.

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

Recently developed surface hoar and near-surface facets are getting gently buried by light snowfall, potentially creating a weak interface which could become reactive with enough new load from snow and/or wind-transport.Other buried surface hoar layers exist in the upper 15-25cm (with sudden test results on these layers in some locations). Soft and hard wind-slabs can be found on certain slopes in the alpine and around treeline. Generally light snowfall amounts are forecast for the region over the next few days. Without the certainty of heavy or rapid loading, it's hard to know when the weight of new snow building over buried weaknesses might reach a tipping point. Areas with locally heavier snowfall should reach this point sooner. Facets at the base of the snowpack could create a deep persistent slab problem that deserves attention in shallow snowpack areas on planar rocky slopes.

Problems

Wind Slabs

An icon showing Wind Slabs
Watch out for wind slabs below ridge crests, behind terrain breaks, and in cross-loaded gullies. Wind slabs are expected to build in size over the next few days.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs
If sufficient new snow builds up, we can expect to see avalanches failing on a persistent weak layer which exists in the upper snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 25th, 2011 8:00AM

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