Avalanche Forecast
Issued: Feb 17th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
shorton,
Avalanche Canada
Heightened avalanche conditions exist on open convex slopes. Avalanches are less likely where thick crusts exist near the surface.
Summary
Confidence
High - We have a good understanding of the snowpack structure and confidence in the weather forecast
Weather Forecast
THURSDAY NIGHT: Cloudy skies with isolated flurries bringing trace amounts of snow (and up to 5 cm along the western Purcells), moderate to strong wind from the northwest, treeline temperatures around -6 C.
FRIDAY: Cloudy with isolated flurries bringing up to 5 cm of snow, moderate wind from the west, treeline temperatures around -4 C with freezing level around 1500 m.
SATURDAY: Cloudy with flurries bringing 5-15 cm of snow by the evening, moderate to strong wind from the southwest, treeline temperatures around -6 C.
SUNDAY: Partly cloudy with scattered flurries bringing another 5-10 cm of snow, light wind from the northwest, treeline temperatures drop to -10 C throughout the day.
Avalanche Summary
No significant human triggered avalanches have been reported over the past week. Explosive cornice control over the past few days has not resulted in avalanches on the slopes below, except for one on Sunday when a cornice fall triggered a size 2.5 slab west of Forster Creek. This avalanche occurred on north aspect at 2250 m and failed on a 40 cm deep surface hoar layer.
Snowpack Summary
5 to 15 cm of fresh snow sits above hard wind-affect snow and melt-freeze crusts in most terrain. The exception could be north-facing terrain at treeline where there may still be soft snow. North-facing treeline terrain also has a 20 to 40 cm deep surface hoar layer that was buried at the end of January. This layer has produced variable results in recent snowpack tests, and could still be reactive on some steep convexities. The lower snowpack is well consolidated, with a crust/facet layer found 80 to 150 cm deep. This layer is currently considered dormant, but could become active later this season as discussed in this forecaster blog.
Terrain and Travel
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Pay attention to isolated alpine features as well as cross-loaded features at treeline.
Problems
Persistent Slabs
Persistent slab avalanches are possible due to a surface hoar layer found 20 to 40 cm deep. While avalanche activity on this layer has been isolated lately, caution should be taken around steep open slopes at treeline, especially in terrain where surface hoar is most likely to be preserved - like cut blocks.
Aspects: North, North East, East, North West.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Feb 18th, 2022 4:00PM
