Avalanche Forecast
Regions: Purcells.
Keep an eye on the snow surface, as it becomes moist from solar input the size and likelihood of avalanches will increase.
Confidence
Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.
Weather Forecast
Tuesday night: possibility of light flurries bringing trace amounts of new snow. Light west winds and a low of -9 at 2000 m.
Wednesday: Sunny with no new snow expected. Light west winds and freezing levels around 1900 m.
Thursday: Sunny with no new snow expected. Moderate southwest winds and freezing levels rising to 2500 m in the south and 2100 m in the north of the range.
Friday: Stormy with rain at lower elevations and up to 5 cm of new snow ain the alpine. Moderate to strong southwest winds. Freezing level around 2300 m.
Avalanche Summary
On Monday ski cutting produced size one wind slab avalanches in steep terrain. Several size one natural dry loose avalanches were also observed in steep unskiable terrain. In the western part of the range several natural wind slab avalanches to size two were observed.
Snowpack Summary
Wind slabs exist in exposed terrain in the treeline and alpine on north and east aspects. A crust exists on or near the surface on all aspects as high as 2500 m. This crust will become moist at lower elevations and to mountain top on sun exposed slopes as the freezing level rises and the sun comes out.Â
A thick rain crust with facets above from early December is buried around 150 cm deep. Large avalanches were naturally triggered on this layer during the last significant warming event in western terrain near the Bugaboos. Significant solar input and warming could wake this layer up again.
Terrain and Travel
- Avoid sun exposed slopes, especially if snow surface is moist or wet.
- Avoid exposure to slopes that have cornices overhead.
- Wind slabs may be poorly bonded to the underlying crust.
Avalanche Problems
Loose Wet
expect wet loose avalanches in steep terrain. Size and sensitivity to triggering will likely increase throughout the day.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2
Cornices
The likelihood of natural cornice falls could increase with solar input. Avoid traveling on slopes with cornices looming above.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Wind Slabs
Wind slabs exist in exposed treeline and alpine terrain. Size and sensitivity to triggering could be greater where wind slab has formed over a crust.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5