Avalanche Forecast
Issued: Dec 27th, 2016 4:00PM
The alpine rating is Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSome light snow and strong winds are keeping the sensitivity of the Dec.19th facet interface elevated. Reports of whumpfing, cracking and natural avalanches over the last 12 hours. Its a tricky time for assessing this problem. SH
Summary
Weather Forecast
Continued strong Westerly winds Wednesday and light snow. Thursday another pulse of snow (10cm) along the divide. Alpine temperatures will stay in the -12 to -15C range and will cool off Friday as a NW flow begins to take over.
Snowpack Summary
Strong winds and light snow accumulations have formed thin wind slabs 10-20cm thick in alpine lees. These sit over previous slabs up to 60cm thick at treeline and above. These wind slabs sit over the poorly bonded Dec.19 facets. The Nov crust is 30-80cm deep. While it is not currently producing avalanches, we expect it could with more snow load.
Avalanche Summary
Numerous size 1.5 - 2 avalanches were observed between Bow Summit and Lake Louise on peaks such as Observation, Crowfoot and Dolomite. These slides appeared to be 24 hours old. As well, 2 naturals were observed off of the N. side of Mt. Fairview today. They were likely initiated by wind transport but the failure layer is unknown.
Confidence
Due to the number and quality of field observations on Tuesday
Problems
Persistent Slabs
Wind slabs up to 60cm+ from last week sit on top of a weak layer of facets (Dec 19 layer). This interface is poorly bonded, resulting in many recent avalanches. Some fresh snow overnight and strong winds are adding to this problem.
Be aware of the potential for wide propagations due to the presence of hard windslabs.Be careful with wind loaded pockets while approaching and climbing ice routes.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 28th, 2016 4:00PM