Avalanche Forecast

Issued: Dec 4th, 2015 3:00PM

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

Avalanche Canada pgoddard, Avalanche Canada

Rising avalanche danger: Time to reel in your terrain exposure.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

A series of storms is coming in quick succession over the next few days. Disagreement between weather forecast models is making it hard to pin down specifics, but you can expect snow, south to south-west winds and fluctuating freezing levels, peaking around 1500 m. Snowfall: 10-20 cm on Saturday, 10-15 cm on Sunday, 20-30 cm on Monday. Locally heavier amounts are quite likely. For more details check out http://www.avalanche.ca/weather.

Avalanche Summary

No new avalanche activity has been reported, but I expect a natural avalanche cycle is already underway in areas with the heaviest new snow and/or wind effect. I would anticipate avalanche sizes to go up through the weekend.

Snowpack Summary

Up to 40 cm recent snow has fallen over a variety of old surfaces including wind-stripped north aspects, hard wind slabs, facets, sun crusts and/or large-sized surface hoar. Of most immediate concern is a crust/surface hoar interface that is already super-reactive. Reports suggest that the surface hoar exists up to about 2000 m and the crust maybe found on all aspects. I wouldn't rule out the possibility of weak interfaces at higher elevations, especially crusts. Strong southerly winds are transporting snow onto lee slopes and creating deep wind slabs. Deeper in the snowpack, surface hoar interfaces that were key players in November seem to be inactive. In the highest and shadiest spots, a crust/facet interface may be found near the ground.

Problems

Storm Slabs

An icon showing Storm Slabs
Snow is building up over a very touchy weak layer and building storm slabs that may be sensitive to human triggering. Winds are also building wind slabs on lee slopes.
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Dec 5th, 2015 2:00PM