Avalanche Forecast

Issued: Dec 27th, 2014 8:00AM

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

ali haeri, Parks Canada

Glacier.

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=http://www.facebook.com/ParksMountainSafetyReactive avalanche conditions have been observed for the past week. This is one of those problems that takes a while to disappear. Be diligently conservative in your terrain selection.

Summary

Weather Forecast

A weak system will be crossing the Interior today giving us light snow ending this evening. Tomorrow will be partly cloudy with lingering flurries. A high pressure ridge is in the works and its effects will be seen starting Monday with colder temperatures and clear skies.

Snowpack Summary

9cm overnight. The widespread Dec 17 surface hoar layer is down ~50-80cm which sits on top of a thick rain crust up to 2100m. A 2cm facet layer between the rain crust has been reactive in snowpack tests with easy results. The Dec 9 surface hoar is down ~ 70-90cm but is more spotty in distribution. The Nov 9 crust is 30cm up from the ground.

Avalanche Summary

Backcountry report from top of Grizzly Shoulder to Puff Daddy, NE facing bowl feature, remotely triggered size 2.0 avalanche, ~2000m, down 50cm, 40-50m wide, 100m long. A second report of a rider triggered avalanche size 1.5 down 55cm and 10-20m wide from another feature in the same area.

Confidence

Due to the number of field observations

Problems

Storm Slabs

A widespread touchy surface hoar layer down 50 to 80cm is likely to be triggered anywhere it has not yet failed. As the slab overtop stiffens it becomes less likely to trigger but propagation and consequences will increase. click photo

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Use conservative route selection, stick to moderate angled terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Deep Persistent Slabs

Storm slab avalanches may step down to deeper layers, including the the Nov 9 layer at the bottom of the snowpack. The resulting avalanche would be very large.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 4

Valid until: Dec 28th, 2014 8:00AM