Avalanche Forecast

Issued: Nov 18th, 2011 9:02AM

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

Avalanche Canada triley, Avalanche Canada

This bulletin is based on limited data. Local variation in conditions and danger levels are likely to exist. To produce more accurate forecasts, we need information. Please send an email to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to limited field observations

Weather Forecast

Drier and colder conditions are forecast for Saturday. Strong easterly winds may occur in the bigger valleys as cold air flows out to the sea. The next storm is expected to hit the north coast as early as Sunday noon. Expect strong winds and heavy precipitation Sunday night and Monday. The freezing levels should rise to near 1000 metres with the new storm.

Avalanche Summary

I suspect there was a decent natural cycle during the storms earlier this week, especially on wind-loaded slopes. The possibility of human-triggered wind and storm slab avalanches is expected to remain for the forecast period.

Snowpack Summary

Another 10-15cm adds to the recent storm snow totals. Varying temperature, precipitation intensity, and wind throughout the recent storms have probably resulted in weaknesses strewn throughout the top metre or so. However, the relatively warm post-storm temperatures on Thursday should favor settlement and strengthening. The mid and lower snowpack is generally well settled and strong, with an old rain crust near the ground. Strong outflow winds from the east may build new wind-slabs on westerly aspects in areas that have snow available for transport.

Problems

Wind Slabs

An icon showing Wind Slabs
Near ridgecrests and terrain breaks, and in cross-loaded gullies.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Storm Slabs

An icon showing Storm Slabs
Steep unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Nov 19th, 2011 8:00AM

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