Avalanche Forecast

Issued: Apr 8th, 2012 10:01AM

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

pgoddard, Avalanche Canada

Sea To Sky.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Monday: Clouds with scattered light precipitation. Freezing level rising to around 1800m. Light southerly winds. Tuesday: Light precipitation. Freezing level rising to around 2400m in the afternoon. Wednesday: Light to moderate precipitation. Freezing level falling to 1500m this evening.

Avalanche Summary

New observations include several loose-wet avalanches up to size 2 from steep solar aspects and cornice fall. Reports from last week include natural activity up to size 3 in response to direct sun-exposure and deep, wide slabs which are suspected to have failed on the late-March interface.

Snowpack Summary

Solar aspects and lower elevations have gone through a melt-freeze cycle for the past few days. Shady north aspects have had some recent surface hoar growth and surface faceting. This sits on around 100 cm of well settled storm snow from last week. A predominately crusty weak interface from late March, now down 50-150cm, remains a potential failure layer for large slab avalanches, especially with heavy triggers such as cornice falls and step-down avalanches. Daytime warming and sun-exposure may cause surface snow to lose cohesion and cornices to weaken.

Problems

Cornices

Large and weak cornices are a hazard in themselves, and can also act as a heavy trigger for very large avalanches on the slope below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

Persistent slabs are becoming less likely, but the potential exists for remote triggering, step down avalanches, and wide propagations, especially during periods of intense solar radiation and daytime warming.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 7

Loose Wet

Loose wet avalanches will become less likely as cloud cover increases, but warm temperatures could cause a continuation of this problem, especially below treeeline.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 9th, 2012 9:00AM