Avalanche Forecast
Regions: Little Yoho.
The snowpack is slowly adjusting, but human triggering remains a risk. The strong to extreme wind and warm temperatures forecast for Thursday will add to the slab development.
Confidence
Moderate
Avalanche Summary
On Thursday, helicopter avalanche control on Mt. Field, Stephen, and Dennis produced slab avalanches up to size 3. Any spot that looked like it could avalanche, did. Many avalanches triggered slabs from the side walls of the path.
Check the avalanche summary in the adjacent Banff forecast for the report of a skier accidental near Lake Louise that happened on Wednesday.
Snowpack Summary
30-35 cm of well-settled storm snow at treeline with mild temps and recent strong S-SW winds created wind and persistent slabs. This snow sits over a layer of weak facets, surface hoar or sun crust from the cold snap.
The mid and lower snowpack is mostly well-settled, though it is heavily facetted in thin snowpack areas. Tree-line snow depths range from 120 cm to 180 cm.
Weather Summary
For Thursday - Friday, flurries with showers at lower elevations are forecast. Freezing levels are 1900 m on Thursday and 2200 m on Friday. Only trace accumulations are expected in the region. Winds will be strong and sustained from the west.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Loose avalanches may step down to deeper layers, resulting in larger avalanches.
Avalanche Problems
Persistent Slabs
Up to 30 cm of storm snow and strong S-SW winds have loaded lee areas at treeline and above with new slabs up to 60 cm deep. This is sitting on a weak layer of facets, surface hoar or sun crust. Human triggering will remain likely in steep or wind loaded terrain for the next few days.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5