Avalanche Forecast
Issued: Jan 18th, 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.
swerner,
Avalanche Canada
Keep an eye on recent wind loading patterns to avoid newly formed wind slabs. A weak basal snowpack structure continues to demand diligent group management. Regroup in safe locations, space out, and avoid shallow rocky start zones.
Summary
Confidence
Avalanche Summary
On Tuesday, human-triggered wind slabs up to size 1 were reported from treeline and above.
Ski cutting in the Fernie area on Monday yielded small (size 1) wind slab releases after the area received 15 cm of new snow. Natural dry loose releases from steep alpine terrain reached size 1.5.
Snowpack Summary
Up to 15 cm of recent snow now settles on wind-affected surfaces above 2000 m and on a crust below 2000 metres.
A crust/facet layer is down 50-90 cm (and 2-15 cm thick at TL elevation). Where it's thickest, it caps a well-settled and consolidated mid-snowpack.
Another crust/facet layer is down 70-150 cm. Below this crust, the basal snowpack is weak and faceted.
Weather Summary
Wednesday Night
Mainly cloudy with isolated flurries 5-10 cm. Ridge winds moderate to strong from the southwest. Freezing level 1000 m.
Thursday
Cloudy with isolated flurries in the morning and sunny periods developing in the afternoon. Moderate southwest winds, potentially strong in the alpine, increasing over the day. Treeline high temperature near -5.
FridayCloudy with sunny breaks. Ridge wind light from the West. Alpine temperatures near -8 and freezing levels valley bottom.
SaturdayMostly cloudy with scattered flurries. Ridge wind moderate from the southwest and freezing levels valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Reactive wind slabs exist at treeline and above.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Weak, faceted grains make up the basal snowpack. Where supportive to riders, a melt-freeze crust may be providing a bridging effect, making it more difficult to trigger deeper layers. Any avalanche triggered this deep will likely be large and destructive. Be especially suspicious of shallow, rocky, or cross-loaded areas with variable snow depths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 19th, 2023 4:00PM
