Avalanche Forecast
Issued: Jan 2nd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
lbaker,
Avalanche Canada
The persistent weak layer is present at all elevations. If triggered it could result in large destructive avalanches. Conservative terrain choices are recommended.
Summary
Confidence
Moderate
Avalanche Summary
In the past few days, we received several reports of previous natural avalanches up to size 2.5. These avalanches released in the facet layer produced during the recent period of arctic air. These avalanches have occurred at all elevations and on a variety of aspects.
Check out this MIN report from our field team for some photos and a good summary of this type of activity.
If you are headed out into the backcountry please consider filling out a Mountain information Network report.
Snowpack Summary
30-40 cm of snow has been redistributed into wind slabs in exposed terrain at treeline and above. In non-wind-affected terrain this recent snow sits on a layer of facets formed during the period of arctic air. Below treeline a thin crust can likely be found at or near the surface.
A surface hoar and facet layer from early December, while spotty, can still be found down around 60cm.
Snowpack depths are highly variable throughout the region.
Weather Summary
Monday Night
Mainly cloudy with clear periods and isolated flurries, trace accumulation. Southerly ridgetop winds 30-50 km/h. A low of -6 at 1500m. Freezing levels valley bottom.
Tuesday
Cloudy with sunny periods and isolated flurries, a few centimeters of accumulation. Ridgetop winds southerly 20 km/h. A high of -4 at 1500m. Freezing levels valley bottom.
Wednesday
Mostly cloudy with sunny periods and isolated flurries, trace accumulation. Ridgetop winds southerly 20 km/h. A high of -5 at 1500m. Freezing levels valley bottom.
Thursday
Mix of sun and cloud. Ridgetop winds southerly 20 km/h. A high of -6 at 1500m. Freezing levels valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- In times of uncertainty conservative terrain choices are our best defense.
- Avoid making assumptions about this layer based on the presence of aggressive tracks on adjacent slopes
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Problems
Persistent Slabs
A layer of facets formed during the period of arctic air is found down 30-50cm. This layer has recently produced natural avalanches at all elevations. It is likely most reactive at treeline where surface hoar could also exist as part of this layer.
Natural avalanche activity has tapered off on this layer but human triggering is still possible.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Southerly winds continue to move what snow is available and build wind slabs at higher elevations. At treeline, windslab may sit over a weak layer of surface hoar buried December 28. Watch for steep and cross-loaded features where wind slabs are possible to human-trigger.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 3rd, 2023 4:00PM
