Avalanche Forecast

Issued: Nov 17th, 2011 9:46AM

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

ccampbell, Avalanche Canada

Northwest Coastal.

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 observationsfor the entire period

Weather Forecast

Friday: Mostly clear with freezing levels at sea level and Alpine temperatures as low as -17 Celcius. Strong Northeasterly outflow winds developing throughout the day.Saturday: Increasing clouds and warming trend as winds shift to westerly, but freezing levels remaining at sea level.Sunday: Light snowfall increasing throughout the day with gradual warming

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.

Problems

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

Steep unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Nov 18th, 2011 9:00AM