Avalanche Forecast
Regions: Banff Yoho Kootenay.
Expect new snow and increasing winds to begin on Monday, this will produce windslabs in our forecast region. There is some uncertainty as to the amount and timing of the event.
Weather Forecast
Temperature inversion breaking down throughout today, clear conditions allowed solar input affecting South facing slopes. Expect winds to pick up sometime on Monday with new snow through to Tuesday.
Snowpack Summary
Hard wind slabs are present in exposed alpine locations with softer snow in sheltered areas. A sun crust is present on most steep solar aspects. The Nov 5 facet/crust combo is down 50-80 cm and producing hard to no results. This crust extends up to 2500 m on N aspects and higher on solar aspects. Snow depths at treeline are 70-130 cm.
Avalanche Summary
There were a few natural loose avalanches observed in south facing terrain in the alpine.
Confidence
Timing of incoming weather systems is uncertain on Monday
Avalanche Problems
Deep Persistent Slabs
The Nov 5 crust has facets above and below it, and exists up to 2500m on shady aspects and higher on solar aspects. We have seen a few large avalanches on this layer over the last couple of weeks. Continue to use caution in steep terrain,
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2.5
Wind Slabs
The previous windslab has become mostly unreactive, with incoming snow and wind expect new windslabs to become a problem. Be aware of immediate lee features as this new snow comes in and be cautious as this problem grows throughout Monday and Tuesday
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 1 - 2