Avalanche Forecast

Issued: Jan 16th, 2012 9:31AM

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

pgoddard, Avalanche Canada

Sea To Sky.

Check daily for updates, as the weather forecast is highly uncertain at present. Avalanche danger ratings are likely to change as we receive updated information.

Summary

Confidence

Poor - Track of incoming weather is uncertain on Wednesday

Weather Forecast

Tuesday: 5-10cm snow. Strong westerly winds. Freezing level at valley floor.Wednesday/Thursday: Weather models show very different outcomes. Anything's possible - from dry conditions to moderate (locally heavy) snowfall, with strong westerly winds and a slight rise in temperature. Confidence is poor. Check in tomorrow for an update.

Avalanche Summary

On Saturday, numerous avalanches were triggered by skiers and explosives. A few small, skier-triggered avalanches were reported on Sunday. They all failed in, or at the base of, the storm snow.

Snowpack Summary

Recent dry snow (10-30cm) fell with little wind and has not developed into a slab in most areas. However, this is likely to change quickly as the wind picks up again. Below this, older wind slabs are stubborn to trigger. A buried rain crust extends to about 1800m. Above this elevation, buried old surfaces include sastrugi and wind slab. Buried surface hoar is not a major concern in the upper snowpack as it is spotty in its distribution and may be isolated to a few sheltered drainages. Concern for lower snowpack layers has diminished and remains only in shallow snowpack areas. Facets associated with a crust from mid-December and/or sugary facets at the base of the snowpack may still be a concern in shallow areas. Fragile cornices are still lurking.

Problems

Wind Slabs

New wind slabs are forming quickly. You'll find them on the down-wind side of ridges and terrain breaks.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Loose Dry

Loose dry snow can sluff easily in steep terrain. In the wrong terrain, it could knock you off your feet, or carry you into a terrain trap.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 17th, 2012 8:00AM