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, Persistent Slabs and Deep Persistent Slabs.
kdevine,
Avalanche Canada
The snowpack is complex and 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
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
THURSDAY NIGHT - Mainly cloudy / light to moderate southwest wind / alpine low temperature near -7Â
FRIDAY - A mix of sun and cloud / light to moderate southeast wind / alpine high temperature near -5Â
SATURDAY - Mainly sunny / light south wind / alpine high temperature near -8Â
SUNDAY - A mix of sun and cloud / light to moderate west wind / alpine high temperature near -7
Avalanche Summary
On Wednesday, there were a few size 1 human triggered wind slab avalanches reported in the region.
On Tuesday, there was a human triggered size 2.5 avalanche reported on an east aspect at treeline in the Lower Holt area, near Golden. Two people were caught in this avalanche but were luckily uninjured. For a full report of this incident, click here.
There was another human triggered avalanche reported in the region on Tuesday on a northeast aspect at treeline near Glacier National Park. The MIN report can be viewed here.
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.Â
A notable avalanche incident occurred on Sunday and can be viewed here.
Snowpack Summary
Recent fresh snow with strong southerly wind 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. 40-60 cm of snow sits on a weak layer of surface hoar that was reported in the Golden area.Â
The mid-December surface hoar is now down 90-140 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 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 new snow and strong southwest winds have likely formed 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 is down 50-100 cm, and may still be easy to trigger in some areas.
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 at least one large avalanches in the past week.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 8th, 2021 4:00PM
