Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Jan 9th, 2013–Jan 10th, 2013
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
3: Considerable
The avalanche danger rating below treeline will be considerable
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
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

Regions: Kootenay Boundary.

Although the danger has dropped to CONSIDERABLE, a very cautious approach is imperative. The mountains have hit the reset button and we need to do the same with our expectations of what is safe to ride.

Confidence

Fair

Weather Forecast

Thursday: Expect mixed skies with some sunny breaks later in the day. Temperatures should reach -10 and winds turn to light northerlies.Friday & Saturday: A ridge dominates giving mixed skies, light northerly winds and cool alpine temperatures. Valley cloud is possible.

Avalanche Summary

Avalanches up to 2.5 have been reported, predominantly windslabs failing naturally and with explosives in lee locations. Isolated rider triggering has also been reported.

Snowpack Summary

The recent storm has brought up to 60cm of snow. Consistent southwest winds have redistributed the new snow (dramatically in some areas) to create widespread windslabbing on lee and open features in the alpine and exposed treeline. Where the wind has been strongest, windslabs are much lower on slopes than normal.There have been avalanches reported both within the storm layers as well as at the initial storm interface, the January 4th layer. This layer consists of small facets, surface hoar (up to 12mm) in sheltered treeline and below treeline areas and sun crust on steep south and west facing slopes. The bonds with the facetted snow are improving while the surface hoar &/or sun crust interface is weak. There are reports of Sudden Planar shears (fast & clean) in compression tests and “Propagation Likely” results in extended column tests on the preserved surface hoar.The midpack is well bonded and strong. The November 28 surface hoar is still being found in isolated, sheltered below treeline locations buried 120cm. The deep crust/facet combo from early November still exists and concern remains (although unlikely) for triggering this layer from a shallow spot or with a heavy load.

Avalanche Problems

Storm Slabs

Rapid settlement is creating a cohesive storm slab
The new snow will require several days to settle and stabilize.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 4

Wind Slabs

New windslabs have formed in immediate lee and cross loaded locations. The winds are strong, meaning more intense slab development and slabbing extending lower on the slopes than normal.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Use ridges or ribs to avoid wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 6