Avalanche Forecast

Issued: Feb 26th, 2016 8:00AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Cornices, Persistent Slabs and Wind Slabs.

jsmith, Avalanche Canada

Kootenay Boundary.

Solar radiation is the primary factor driving the hazard this weekend. Expect conditions to change rapidly if the sun comes out.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

No significant snow in the forecast. Up to 5cm Friday night and another 5-10cm Sunday. Light to moderate ridgetop winds out of the southwest throughout weekend. Freezing levels spike Friday then cool off to around 1800m for the remainder of the period. For more detailed weather information see http://www.avalanche.ca/weather

Avalanche Summary

On Thursday two size 1 skier triggered slab avalanches were reported on northerly aspects that failed on a surface hoar layer down 20-25cm. The elevations of these avalanches were not reported.

Snowpack Summary

Cornices are large and looming. Old wind slabs are well bonded but could fail with daytime heating on solar aspects. The mid February layer is down 30-50cm and is a crust in most areas. This layer is generally well bonded to the overlying persistent slab. However, in isolated areas on northerly aspects at treeline elevations the February 10th surface hoar down 70-100cm is still producing moderate sudden planar shears in compression tests, though it has not been reactive to human triggers. This suggests a classic low probability, high consequence scenario.

Problems

Cornices

Avoid cornice threatened slopes if sun comes out.

Do not travel on slopes that are exposed to cornices overhead.>Cornices become weak with daytime heating. >

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Persistent Slabs

This is still a layer to keep in mind, as an avalanche on this layer could be large and destructive.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Wind Slabs

Solar radiation greatly increases the reactivity of wind slabs.

Extra caution needed if sun comes out.>

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 27th, 2016 2:00PM