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Avalanche Forecast

Feb 16th, 2017–Feb 17th, 2017
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
2: Moderate
The avalanche danger rating below treeline will be moderate
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
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: North Columbia.

Be aware of conditions that change with elevation and expect touchy fresh storm and wind slabs at higher elevations.

Confidence

Moderate - Forecast snowfall amounts are uncertain on Saturday

Weather Forecast

FRIDAY: Unsettled conditions with isolated flurries, moderate becoming light southwesterly winds and freezing levels dropping to 1400 m.SATURDAY: Cloudy with flurries bringing another 2-5 cm overnight, light winds and freezing levels around 1000 m.SUNDAY: Cloudy with light flurries, light southerly winds and freezing levels around 1300 m.

Avalanche Summary

Reports from Wednesday and Thursday morning include continued natural and skier-triggered loose wet avalanche activity up to Size 1 on steep slopes. On Monday a natural Size 2 wind slab was observed on a northeast aspect at 2100 m failing down 40 cm. Explosives triggered a few Size 2-3 persistent slabs failing on the early February weakness down 50-60 cm. Touchy new wind and storm slabs are sensitive to light triggers and have the potential to step down and trigger persistent slab avalanches.

Snowpack Summary

Expect to find 20-30 cm of fresh snow blown into touchy wind slabs at higher elevations, and wet and cohesionless rain-soaked snow at lower elevations, which should soon freeze into a solid crust. Rapidly settling storm snow from last week is still bonding poorly to the previous snow surface from early February, which is now down 60-80 cm and includes a sun crust on steep sun-exposed slopes, faceted snow, as well as surface hoar on sheltered open slopes. The mid and lower snowpack are generally well settled and stable in deeper snowpack areas but may be faceted and weaker in shallower areas. The mid-December surface hoar/facet persistent weakness can now be found down roughly 150 cm. It has become inactive in the south of the region, but may still be lingering in the northern part of the region near Blue River and Valemount.

Avalanche Problems

Persistent Slabs

A persistent weakness down 50-80 cm remains remains sensitive to light triggers in isolated areas. Smaller avalanches have the potential to step down to this layer.
Whumpfing, shooting cracks and recent avalanches are all strong indicators of unstable snowpack.Be aware of the potential for large avalanches due to the presence of buried weak layers.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3

Wind Slabs

Touchy fresh wind slabs are likely lurking below ridgecrests and behind terrain features at higher elevations.
Avoid freshly wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2