Archived

Avalanche Forecast

Nov 16th, 2011–Nov 17th, 2011

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: 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.

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.

Avalanche 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