Avalanche Forecast
Regions: Little Yoho.
Finding areas where there is no significant wind effect and/or lingering wind slab will lead you to the safest and most enjoyable travel. As the cold continues to weaken the snowpack, skiers/riders in steeper terrain features report triggering sizable loose dry avalanches.
Confidence
High
Avalanche Summary
No new avalanches were reported Thursday or Friday.
On Thursday & Friday, Sunshine reported up to size 1.5 windslab avalanches with explosives and ski cuts, generally 30-50 cm deep hard slabs failing on a weak facet layer with propagations up to 25 m.
Also on Friday, sizable loose dry avalanches were skier triggered in steep terrain near Lake Louise.
On Tuesday we investigated the Quartz skier accidental wind slab avalanche, triggered from a shallow spot.
Snowpack Summary
25-30cm of settled snow from last week has been redistributed by the wind in exposed locations, burying the Jan 30 weak layer, and in isolated locations formed now what are aging wind slabs. Specific areas exposed to the wind may have strastrugi. The mid and lower snowpack is well settled, with tree-line snow depths ranging from 120 cm to 180 cm.
Weather Summary
Friday night: Cloudy periods with scattered flurries without much accumulation. Alpine temperature: Low -16 °C with Light westerly ridge wind.
Saturday: Mix of sun and cloud, scattered flurries without much accumulation. Alpine temperature: High -13 °C. Light ridge NW wind becoming SW.
Sunday: Cloudy with scattered flurries. Alpine temperature: Low -16°C, High -13 °C. Ridge wind light South.
Terrain and Travel Advice
- Be careful as you transition into wind-affected terrain.
- Wind slabs are isolated, but may remain reactive.
- Closely monitor how the new snow is bonding to the old surface.
Avalanche Problems
Wind Slabs
Lingering hard wind slabs exist on alpine lee features. Potential failure planes are old weak facet layers or the Jan 30 layer of facets, sun crusts, and isolated surface hoar beneath the recent snow.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2