Avalanche Forecast
Issued: Jan 20th, 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.
trettie,
Avalanche Canada
Avoid wind loaded features, especially at ridge crests and on shallow rocky slopes. You may not see signs of instability but the layers are still there.
Summary
Confidence
Avalanche Summary
On Thursday our field team observed a few natural size one wind slabs. These slabs released on lee features just below cornices. See their MIN report for more details.
Although there has been a decline in observed avalanche activity, triggering a large persistent slab avalanche remains possible and terrain should be chosen with care.
Snowpack Summary
New snow is gradually accumulating above settled snow from last week's warm storm. Wind slabs will likely be found on higher elevation north and east slopes. At lower elevations, a rain crust exists near the surface, with reported elevations extending up to 1800 m in the Cariboos and roughly 1200 m in the northern part of the region.
Check out this MIN from our field team for more details on the concerning layers in the snowpack.
Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. One is a recently buried surface hoar layer found 30 to 50cm deep in sheltered terrain features at treeline and above. At this same depth, a crust exists on steep south facing slopes. Another layer of facets, crust, and surface hoar was buried around Christmas and is now 40 to 80cm deep. Finally, a layer of large, weak facets buried in November is found near the bottom of the snowpack. This layer is likely most problematic in alpine terrain, where shallower avalanches could scrub down to these basal facets.
Recent observations suggest the buried weak layers are gaining strength, but not enough to trust them in high consequence terrain.
Weather Summary
Friday Night
Cloudy with a few centimeters of new snow expected. Moderate to strong southwest winds and a low of -10 at 1800m.
Saturday
Cloudy with up to 5cm of new snow. Moderate to strong southwest winds and a high of -5 at 1800m.
Sunday
A mix of sun and cloud with light flurries bringing trace amounts of new snow. Moderate northwest winds and a high of -9 at 1800m.
Monday
Stormy with up to 10cm of new snow expected. Strong west winds and a high of -6 at 1800m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection and resist venturing out into complex terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Be carefull around freshly wind loaded features.
Problems
Persistent Slabs
Several buried weak layers remain a concern for human triggering. At treeline elevations, the main concern is surface hoar and crust layers in the middle of the snowpack, especially on steep convex openings. In the alpine, the main concern is weak facets at the bottom of the snowpack, especially on rocky slopes with variable snow depths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Winds have varied in the past few days. Wind slabs could be found on all exposed terrain at treeline and above.
Avoid thin rocky features near ridgetops where wind slabs and deeper layers are most likely to be triggered.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 21st, 2023 4:00PM
