Avalanche Forecast

Issued: Nov 16th, 2011 8:40AM

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

Sea To Sky.

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

Thursday: Expect another 5-15cm of new snow as the storm tapers off. Freezing levels should lower to around 300m and winds should ease off becoming light to moderate westerlies.Friday: Isolated flurries bringing light amounts with freezing levels as low as 200m and light northwesterly winds.Saturday: Relatively clear, dry and cold with light northwesterly winds.

Avalanche Summary

No reports of avalanches, but I suspect wind slabs and any new storm slabs will be susceptible to human triggering. The size of the ensuing avalanche depends on slab thickness, with slabs thicker than 30cm generally producing avalanches sufficiently large to bury or injure a person.

Snowpack Summary

Total snowpack depth at treeline is around 80-100cm. Expect to find deeper pockets of wind-blown snow immediately down-wind of terrain features and ridge crests. A rain crust from last week is 70 or 80 cm off the ground at treeline and lower alpine elevations, and is heavily faceted faceted in some locations. Watch this weakness as it gets more load.

Problems

Wind Slabs

Near ridgecrests and terrain breaks.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

Steep slopes with enough snow on the ground to smooth any roughness in areas with sufficiently intense storms to form thick cohesive slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 17th, 2011 3:00AM