Avalanche Forecast
Issued: Feb 16th, 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 steep convex slopes. Avalanches are less likely where thick crusts exist near the surface.
Summary
Confidence
Weather Forecast
WEDNESDAY NIGHT: Partly cloudy skies with light flurries along the northern and western Purcells with up to 5 cm of new snow possible, moderate wind from the northwest, treeline temperatures drop to -10 C.
THURSDAY: Cloudy with scattered flurries bringing up to 5 cm of snow along the northern and western Purcells, moderate to strong wind from the west, treeline temperatures around -5 C with freezing level climbing to 1200 m.
FRIDAY: Mix of sun and cloud, light flurries along the western Purcells bringing a trace of snow, moderate wind from the northwest, treeline temperatures around -3 C with freezing level around 1500 m.
SATURDAY: Cloudy with flurries bringing 5-10 cm of snow, moderate wind from the southwest, treeline temperatures around -5 C with freezing level around 1200 m.
Avalanche Summary
No significant human triggered avalanches have been reported over the past week. Explosives have broken some large cornices over the past few days, but for the most part these have not triggered slabs on the slopes below. One exception was on Sunday when a cornice 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 overlies a variety of surfaces. Higher elevations are heavily wind effected with a melt freeze crust on solar aspects. Lower elevations hold a widespread thick melt freeze on all aspects with surface hoar sitting above the crust in sheltered terrain. The late January interface is buried 20 to 40 cm deep, and consists of a melt-freeze crust at lower elevations and on solar aspects extending into the alpine. Surface hoar sits above the crust in sheltered areas at treeline and below. The snowpack below is well consolidated, with the early-December crust/facet persistent weak layer buried 80-150 cm deep. It is currently considered dormant. We expect this layer to become active later this season, check out the forecaster blog for more information.
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 50 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. Avalanche activity is less likely where a thick and supportive crust sits on the surface.
Aspects: North, North East, East, North West.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Feb 17th, 2022 4:00PM
