Avalanche Forecast
Regions: Little Yoho.
Winds, warming, and a bit of snow expected to arrive this weekend will be a significant change that could really shake up the snowpack. Make conservative terrain selections and consider your exposure to overhead terrain. Natural activity is expected.
Weather Forecast
A low pressure system will cross the divide Saturday. As temperatures rise 10 to 15 degrees C, expect alpine winds to reach extreme values by the afternoon as light snowfall starts on the divide. Snow continues at a moderate rate for Sunday as the winds diminish to strong midday and temperatures rise a further 10 degrees C.
Snowpack Summary
10-40 cm of snow last week and recent wind from various directions has developed wind slabs in the alpine. There is 80-100+ cm over the Dec. 2 crust/facet combo in Little Yoho which exists below 2200m and are monitoring closely. HS at treeline is 180-260cm
Avalanche Summary
There was a skier triggered size 2 avalanche at 2000m in Kootenay NP Thursday. This appears to have been on the Dec. 2nd crust/facets. It also appears that another party triggered a smaller slab in the same area today. The ski hills worked with recent windslabs in the alpine yesterday however nothing new was reported today.
Confidence
Intensity of incoming weather systems is uncertain on Saturday
Avalanche Problems
Wind Slabs
Last week's snow and winds from a variety of directions have created wind slabs in the alpine. As winds increase through Saturday we expect natural activity in the alpine and slab development at treeline.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Loose Dry
A long period of cold has lead to faceting of the upper snowpack. This weak snow will be more sensitive to triggering and will also allow avalanches to run further and faster. We expect the wind to generate a significant amount of loose dry activity.
- Be careful of loose dry sluffing in steep, confined or exposed terrain.
- Loose dry avalanches could easily trigger Wind Slab or Persistent Slab avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1.5