Avalanche Forecast

Issued: Jan 23rd, 2014 7:21AM

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

Avalanche Canada jfloyer, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

A high pressure ridge will continue to bring dry, warm conditions.Friday and Saturday: An inversion will generate an above freezing layer from around 1800 to 3200m. Expect some cloud around 1800 m as well as some strong alpine sunshine. Alpine temperatures will reach around +5C and will feel higher still in the sunshine. Ridgetop winds 20-30 km/h from the NW.Sunday: A cooler day as far as air temperatures go, but cloud dissipating, so treeline areas may actually feel warmer. Winds light northerly.

Avalanche Summary

On Tuesday, two size 2.5 avalanches released on the same slope about 50 m apart. They failed to ground and it is thought that one released naturally and the other released sympathetically in response to the first. These have been the only avalanches reported since a sporadic cycle of larger avalanches running on weak basal layers ended on Saturday 18th.

Snowpack Summary

Snowpack depths vary, but in general there is now 200 to 250cm of snow at tree line and as much as 300 cm in select places in the alpine. In the south and to the east of the region, there are still areas with a relatively thin snowpack. The recent dry, warm weather has generally consolidated the upper snowpack. Old, stubborn hard wind slabs may exist under a skiff of new snow. Steep, sun exposed features are most likely seeing a daily melt-freeze cycle, that could see new snow shed readily, especially where it overlies recently buried surface hoar that lies approximately 10 cm under the surface.A basal facet/crust combo (weak sugary snow above and below a crust) near the ground is still a concern in some areas, and was the culprit with some of the very large recent avalanches. Likely triggers at this interface would include cornice fall, rapid temperature changes or thin spot triggering on an unsupported alpine or treeline elevation slope.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Deep persistent activity has lingered longer in this region than in others. Be mindful of thin, rocky areas in steep, convex alpine terrain.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Avoid convexities or areas with a thin or variable snowpack.>Conditions have greatly improved, but be mindful that deep instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Jan 24th, 2014 2:00PM