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Avalanche Forecast

Feb 2nd, 2016–Feb 3rd, 2016
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
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
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: Sea To Sky.

Enjoy the much improved riding conditions but keep an eye out for terrain traps where the consequences of being caught in a small sluff or slab could be severe.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

WEDNESDAY: Periods of snow with up to 5cm of accumulation and freezing levels around 800m with moderate southerly winds. THURSDAY: Up to 10cm fresh snow overnight and continued light snow flurries throughout the day bringing another 1-3cm. The freezing level is expected to rise to near 1000m with moderate southwesterly ridgetop winds. FRIDAY: Moderate to heavy snowfall with 20-30cm of accumulation and freezing levels rising to 1500m.

Avalanche Summary

Reports from Monday include more evidence of the widespread large slab avalanche cycle associated with heavy loading from snow, wind and rain over the weekend. Skier testing and explosives control on the weekend produced several Size 1-1.5 soft slabs from immediate lee features and loose dry avalanches on steep slopes. There were also reports of a couple Size 1 accidentally triggered wind slabs from steep leeward alpine slopes.

Snowpack Summary

Up to 50 cm of dry new snow sits on 60-80 cm of moist settled snow from last week's warm storm system, or a rain crust below around 1800 m. Expect to find pockets of fresh wind slab in exposed lee terrain and the potential for loose dry avalanches on steep open slopes. Cornices are also becoming large and potentially weak. Where it still exists, the mid-January surface hoar layer may be found between 100 and 180 cm below the surface. The combination of heavy storm loading and warm temperatures has likely flushed out this weak layer in most areas. However, there is still some uncertainty regarding the sensitivity and distribution of this persistent avalanche problem, especially at high elevations in the north of the region where it remains reactive in snowpack tests (hard to initiate but sudden "pops" results).

Avalanche Problems

Wind Slabs

Triggering fresh soft wind slabs is possible in exposed lee terrain near ridge crests, especially on steep unsupported slopes.
Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Dry

Cold dry snow could sluff easily in steep terrain.
Be cautious of sluffing in steep terrain.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 2

Cornices

Cornice falls can be destructive by themselves, but can also be a trigger for surprisingly large avalanches on the slope below.
Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 4