Avalanche Forecast

Issued: Dec 9th, 2014 8:24AM

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

percy woods, Parks Canada

Glacier.

Rapid warming and precipitation are leading to an increasing avalanche hazard. Be cautious crossing run out zones and limit exposure to overhead hazards.

Summary

Weather Forecast

Today a rapid warming trend with above freezing temperatures and rain mixed with snow are forecast for all elevations. Tomorrow the warming trend is expected to continue with large amounts of rain and snow with moderate to strong winds.

Snowpack Summary

5cm of snow over night adding to the15-20cm of recent storm snow is over the Dec 5 surface hoar/facet layer and sun crust on steep solar aspects. The storm snow resides over a breakable crust below 1600m. The Nov 21 and Nov 9 persistent weak layers are now buried down ~105 and ~140cm. It is already above freezing at tree line.

Avalanche Summary

No new avalanches were recorded in the last 24hrs. Rising temperatures and heavy forecast precipitation will result in a rapidly rising avalanche hazard.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Storm Slabs

Rapid warming with mixed rain and snow is leading to an increasing avalanche hazard. Recent storm snow may be sitting on good sliding surfaces such as surface hoar and crust.

Plan to be off big slopes before the temperatures rises and the snowpack deteriorates.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Persistent Slabs

Trigger points for the persistent weak layers buried down ~1m and ~1.3m include steep alpine terrain, thin areas, and unsupported open slopes. Once initiated avalanches triggered in the storm snow may step down to the deep persistent weak layers.

Sluffs may trigger deeper instabilities.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 10th, 2014 8:00AM