Avalanche Forecast
Issued: Dec 13th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
TT,
Avalanche Canada
While the lack of fresh snow may tempt some to explore into more exposed terrain, it is important to stay conservative in your ski line choices. The persistent weak layer is becoming more unstable with faceting snow below. Be especially cautious in areas where upper snowpack forms a more cohesive slab.
Summary
Confidence
Avalanche Summary
Yesterday's road patrol on the Icefields Parkway observed a natural size 1.5 avalanche in the alpine. This avalanche is estimated to have occurred a few days ago running on the persistent weak layer. Explosive control at Marmot ski resort at tree line and alpine has been producing small results mostly running within new snow and occasionally scrubbing to the persistent weak layer in the last few days.
Snowpack Summary
5-10cm of recent snow overlies previous wind slab in the alpine. At tree line and below a surface hoar layer can be found down 25-35cm in sheltered areas and generally rests on facetted snow to ground. The snowpack ranges from 40-100cm deep and can be unsupportive in locations.
Weather Summary
The weather pattern is expected to be quite stable over the next three days. Expect a mix of sun and cloud with no precipitation and alpine temperatures hovering between -10 °C and -5 °C. Ridge winds will be light to moderate out of northwest.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- If it's deep enough to ride, it's deep enough to slide (avalanche).
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Persistent Slabs
Marmot Basin Ski area reports surface hoar extending into some alpine features. Solar crust on south aspects is spotty but also of concern. Dig and assess this layer before committing to terrain. This layer has a potential to scrub down to facets below. Lots of whumpfing and shooting cracks have been observed on this layer across Jasper but no avalanches have been observed yet. Below tree line hazard is rated low but caution is advised in isolated steep open slopes with signs of slab development.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
As old wind slabs are becoming less reactive over time, forecasted northerly winds are suspect for reverse and cross loading. If triggered, wind slabs have a potential to step down to the persistent weak layer resulting in larger avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 14th, 2022 4:00PM
