Archived

Avalanche Forecast

Dec 7th, 2014–Dec 8th, 2014

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

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast.

This Will be a Week of Dubyas: Windy, Wet and Warm! Expect increasing hazard and widespread natural avalanche activity by Tuesday.

Confidence

Fair - Due to the number of field observations

Weather Forecast

Monday: Cloudy with rain or snow increasing in intensity later in the day. The freezing level is around 1800-2000 m and winds are 30-50 km/h from the S-SW. Tuesday: Rain, heavy at times. The freezing level could climb as high as 2300-2500 m and winds could be gusting close to 100 km/h from the south. Wednesday: Continued heavy rain or snow. The freezing level remains above 2000 m and southerly winds should keep cranking.

Avalanche Summary

No new reports of avalanches but I expect this will be an active week. A natural avalanche cycle is likely with potential for some large, deep slides. Please let us know what you're seeing out there at forecaster@avalanche.ca.

Snowpack Summary

Around 10-15 cm of moist new snow now covers the previous variable snow surface that consisted of facets (dry sugary snow) and surface hoar in sheltered areas, or pockets of old wind slab and an ice crust in open wind-exposed terrain (depending on aspect). Fresh new wind slabs may have formed in open north and east facing slopes, especially below ridges and behind terrain features in the alpine. There are probably a couple notable crusts in the upper to mid snowpack. The deeper crust may be associated with a weak layer of facetted snow, but may be limited to slopes at and above treeline. One recent snowpack test on this layer in the northwest part of the region produced a sudden "pops" result down 80 cm on a north aspect at treeline. Snow pack depth and snow quality drastically diminishes as you drop below treeline.

Avalanche Problems

Storm Slabs

Dense and moist storm slabs will start to develop this week, primarily above treeline. The new snow may not bond well and could trigger deeper weaknesses in the snowpack. Also, watch for deep wind slabs in NW-NE facing terrain.

Be alert to conditions that change with elevation and avoid wind loaded slopes near ridge crests.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Loose Wet

Watch for loose wet sluffs in steep open terrain and in gullies.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be aware of party members below you that may be exposed to your sluffs.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2