Avalanche Forecast
Regions: Jasper.
Facetting has refreshed the available snow for transport. Expecting a cold, weak new interface in lee features at all elevations. Stay away from steep terrain traps.
Weather Forecast
Sunday: Mainly cloudy with scattered flurries. 5-10 cm. Temp: High -13 °C. Wind SW: 15 km/h.
Monday: Mainly cloudy with scattered flurries. 4 cm. Temp: Low -18 °C, High -10 °C. Wind S: 10-30 km/h.
Tuesday: Mainly cloudy with isolated flurries. Trace over the day. Temp: Low -28 °C, High -16 °C. Light ridge wind.
Snowpack Summary
Cold temps are penetrating deep into the upper snowpack, promoting faceting. Wind slab pockets are present on all aspects, tree line and above. The mid-pack is supportive with the Dec 1st interface down ~40 cm in most locations. Basal faceting continues below the Nov 5 crust potentially amplifying the deep persistent slab problem.
Avalanche Summary
Friday's Maligne patrol noted several loose dry up to size 1.5 running far on a previous hard surface. Avalanche Control on Medicine Slabs (steep, open treeline) produced several loose dry, and fast moving facet avalanches to the road.
Confidence
Intensity of incoming weather systems is uncertain on Sunday
Avalanche Problems
Wind Slabs
Variable wind direction over the past week has caused reverse loading in some areas. A 100km/hr wind event Sunday night has the potential to raise the Wind slab hazard for Sunday and Monday with potential for loading to occur further down slope.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Variable winds have created pockets of wind slab on all aspects.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5
Loose Dry
Significant activity of this nature was noted in the Maligne range. Cold temperatures continue to cause the surface snow to loose its structure and be active particularly on steep alpine features and can run uncharacteristically far.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2
Deep Persistent Slabs
Recent avalanche observations have shown that deep persistent slabs can be initiated by large triggers such as surface avalanches or cornice failures.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1.5 - 3