Avalanche Forecast
Issued: Jan 5th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
kdevine,
Avalanche Canada
Fresh wind slabs are likely to be encountered at upper elevations. Watch for signs of instability such as whumpfing, cracking, and recent avalanches.
Concern remains for persistent weak layers, which are best managed through conservative terrain choices.
Summary
Confidence
Weather Forecast
TUESDAY NIGHT - Cloudy with a few flurries, 5 cm / strong southwest wind / alpine low temperature near -8
WEDNESDAY - Mainly cloudy with a few flurries, 5cm / moderate southwest wind / alpine high temperature near -5 / freezing level 1400 m
THURSDAY - A mix of sun and cloud / light northeast wind / alpine high temperature near -6
FRIDAY - Mainly sunny / light northeast wind / alpine high temperature near -6
Avalanche Summary
At the time of publishing, there was a preliminary report of a human triggered size 2.5 avalanche north of Kicking Horse on Tuesday. It is suspected that this avalanche ran on a persistent weak layer that was buried in December.
There were a few reports of natural and explosives triggered size 2-2.5 wind and storm slab avalanches on Monday.
On Sunday there were reports of numerous natural, human and explosives triggered avalanches up to size 2. There was also one natural size 2.5 deep persistent slab avalanche reported on a north aspect at 2500 m near Invermere.
NOTABLE MIN from Sunday Here.
On Thursday, a ski cut resulted in a size 2 persistent slab avalanche on a northeast aspect in the alpine near Kicking Horse Mountain Resort. MIN report HERE.
These recent avalanches are a reminder that when persistent slabs are the problem, conservative terrain choices are the answer.
Snowpack Summary
Recent fresh snow with strong southwest wind overnight has likely formed wind slabs in leeward terrain features at upper elevations.
There are currently several layers of concern in much of the region's snowpack. 40-50 cm of snow sits on a weak layer of surface hoar that was reported in the Golden area.
The mid-December surface hoar is now down 90-130 cm. Although there have been no new reports of avalanches on this layer in the last few days, it remains possible to trigger where it is well preserved. There may also be a crust near, or instead of this layer in some areas.
The lower snowpack is characterized by more crusts, the most notable is a rain crust from early November that is sitting near the base of the snowpack, surrounded by a weak layer of sugary facets. It is most likely to be reactive to human triggers in steep, shallow, rocky areas with a thin to thick snowpack.
Terrain and Travel
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Wind Slabs
Recent fresh snow and strong southwest winds have likely formed new wind slabs in lee terrain.
Aspects: North, North East, East, South East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A weak layer of surface hoar down 50-100 cm has been reactive to human triggers in the past week.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
A crust buried near the bottom of the snowpack has been responsible for a few large avalanches in the past week.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 6th, 2021 4:00PM
