Avalanche Forecast
Regions: South Rockies.
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
TUESDAY: Mostly sunny, moderate west winds, treeline temperatures around -22 C.WEDNESDAY: Mix of sun and cloud, strong west winds, treeline temperatures around -20 C.THURSDAY: Cloudy with flurries starting in the afternoon, strong west winds, treeline temperatures around -17 C.
Avalanche Summary
On Sunday, a skier east of the divide triggered a size 2 slab from low on a slope that propagated up and across the slope. The avalanche occurred on a northeast aspect at 1800 m and failed on 50 cm deep crust. This is the only recent report of a human triggered avalanche in the region, but highlights the ability for persistent slab avalanches to have wide propagations. The current forecasters' blog has additional advice on managing the current persistent slab problem (click here).
Snowpack Summary
Cold temperatures are preserving fresh snow from the past week, with up to 80 cm in southern and eastern parts of the region and 50 cm in the Elk Valley. The snow has been deposited into harder wind slabs in exposed terrain, but remains low density in sheltered areas. The main question in the snowpack surrounds the layer sitting beneath the new snow. The layer includes old crusts, wind scoured surfaces, and large feathery surface hoar crystals in sheltered terrain at and below treeline. The distribution of the layer, as well as the properties of the snow above it, is variable. The most suspect areas are where the wind has blown extra snow above this layer and on slopes with preserved surface hoar.Two crusts that were buried near the end of November can be found lower in the snowpack. A third crust from the end of October exists near the base of the snowpack. Recent testing on these crusts has not produced significant results.
Avalanche Problems
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Wind Slabs
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2