Avalanche Forecast
Issued: Jan 7th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
Though avalanche danger may be decreasing, the potential exists to trigger persistent slab avalanches. While these avalanches are becoming less likely, the consequences are high. The uncertainty associated with complex snowpacks is best managed with conservative terrain choices.
Summary
Confidence
Weather Forecast
THURSDAY NIGHT - Cloudy with clear periods / light to moderate south wind / alpine low temperature near -8
FRIDAY - A mix of sun and cloud / moderate to strong south wind / alpine high temperature near -5
SATURDAY - A mix of sun and cloud / light south wind / alpine high temperature near -7
SUNDAY - A mix of sun and cloud / light south wind / alpine high temperature near -6
Avalanche Summary
Wind slabs are likely widespread in lee terrain in the alpine and open treeline areas and they may be reactive to human triggering.
Although the persistent slab problem is trending towards being less reactive, the possibility still exists to trigger it, and these avalanches would likely be large.
Field observations in this region are limited. If you get out, please consider submitting your observations to the Mountain Information Network.
Snowpack Summary
20-50 cm of recent fresh snow now reportedly sits on a weak layer of surface hoar in many areas. It is suspected that his layer is most prevalent at treeline and below treeline. Recent strong winds have redistributed the storm snow and created wind slabs in lee terrain, especially at higher elevations.
A persistent weak layer is now down about 70-100 cm. The distribution of this layer is variable. In some areas, it's surface hoar and/or a crust. In other areas, this layer may be difficult to find, if it exists at all. This layer has been reported as very prevalent in areas near Valemount.
There is a prominent crust near the base of the snowpack. This crust likely has weak facets above and/or below it. There have been no recent avalanches reported on this layer, but would be most likely to trigger in steep, shallow, rocky terrain, with a thin to thick snowpack.
Terrain and Travel
- Be especially cautious as you transition into wind affected terrain.
- Avoid freshly wind loaded terrain features.
- Be aware of the potential for large avalanches due to the presence of buried surface hoar.
- Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.
Problems
Wind Slabs
Recent strong winds have formed widespread wind slabs in lee terrain at upper elevations.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
There are two persistent weak layers of concern within the snowpack. The shallower one consists of surface hoar and is down around 20-60 cm.
The second layer is more variable but consists mainly of surface hoar down 70-100 cm. This layer has been found to be most prevalent at treeline and below treeline in areas near Valemount. In some areas, this layer may exist as a crust.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Jan 8th, 2021 4:00PM
