Avalanche Forecast
Issued: Mar 5th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
JMackenzie,
Avalanche Canada
Not much improvement in recent days. Wind slabs are still sensitive to human triggering and some natural activity has been occurring. We sound like a broken record, but this is a year to stick to low-angle slopes and limit exposure to overhead terrain.
Summary
Confidence
Moderate
Avalanche Summary
One size 2 naturally triggered slab avalanche was observed on Mt Rundle in a steep alpine bowl on a NE aspect on Saturday. This avalanche appeared to fail in the deep persistent weak layer of basal facets. On Friday a size 2 avalanche was observed in the Buller Mountain area that was triggered by a cornice collapse.
Snowpack Summary
Sheltered areas may have some soft snow on the surface giving decent skiing if you can avoid the tracks. However, at treeline and above expect widespread wind slab conditions that have been producing natural and skier-triggered avalanches over the past few days. Easy shears persist down 25 to 35cm, and moderate shears have also been found down 30 to 50cm on various versions of old wind slab interfaces. The midpack is strong in deeper snowpack regions near the divide, but is less supportive in areas with only 100cm of snow on the ground. The basal facets/depth hoar persist and continue to give concern for full depth avalanches.
Weather Summary
There is a fair amount of disagreement in weather models for Monday. Some forecasts are calling for mainly sunny conditions, while others predict overcast skies with very light flurries. Everyone seems to agree that the morning will be a chilly -22C with temps rising to -10C or warmer by midday. Winds should be in the moderate range from the south at ridgetop. If any snow does arrive it will only be trace amounts.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Wind Slabs
Recent variable strong winds have created and added to previous wind slabs that formed in Alpine and Treeline areas. In addition, there are several iterations of buried wind slabs formed in previous wind events down 30 to 50cm in the snowpack. All of these slabs are sensitive to human triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The alpine is still variable in total amounts of snow but the basal layers haven't changed. The entire lower half is either facets, or depth hoar. Thin weak areas should be treated as suspect and avoided.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 6th, 2023 4:00PM
