Avalanche Forecast
Issued: Jan 6th, 2025 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.
Parks Canada,
Avalanche Canada
Change is coming as a notable period of calm weather comes to an end.
Be aware of increasing winds on Tuesday: these winds are expected to increase natural avalanche activity in the region.
Summary
Confidence
Moderate
Avalanche Summary
A field team on a flight with perfect visibility throughout Banff, Yoho and Kootenay observed a few natural size 2 windslabs in lee alpine terrain and a cornice failure that ran further than expected.
Snowpack Summary
20-40 cm unconsolidated snow sits on the surface, waiting to be blown by incoming winds. The mid-pack is generally strong but a weak crust/facet layer can often be found near the ground, particularly in shallower areas. At treeline, average snowpack depths are 120-150 cm. The snowpack in Little Yoho is generally deeper and more consolidated than in areas further east in the BYK region.
Weather Summary
The story of the next few days is wind. After a period of very calm conditions, the winds are forecasted to increase throughout the day on Tuesday. Expect strong to extreme ridgetop winds overnight on Tuesday and Wednesday. Temperatures will remain cold (-5 to -15 at treeline) and minimal to no snow accumulation by Friday.
Terrain and Travel Advice
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Wind Slabs
Forecasted winds on Tuesday will blow the 20-40 cm of loose dry snow on the surface and create sluffing and windslab conditions. We expect avalanche activity to increase as the winds increase throughout the day.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
The surface snow will sluff easily in steep alpine terrain as the winds pick up on Tuesday.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
In shallow snowpack areas (eg. windblown ridges or crossloaded slopes), weak facets and depth hoar associated with old crusts can be found near the base of the snowpack. Avoiding thin areas will help limit your exposure to this problem.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 7th, 2025 4:00PM
