Avalanche Forecast
Regions: Purcells.
Confidence
Fair - Freezing levels are uncertain on Saturday
Weather Forecast
Saturday: Light snow, starting late in the day. Moderate to strong W winds. Alpine temperature near -6.Sunday: Light to moderate snow. Moderate to strong NW winds. Alpine temperature near -7.Monday: Light snow. Light SW winds. Alpine temperature near -12.
Avalanche Summary
A widespread natural avalanche cycle was observed over the last two days, including loose dry and soft slab avalanches at the beginning of the storm, and wet avalanches as it warmed up. Skiers also triggered wind slabs on lee slopes. Most avalanches were in the size 1-2 range (with a few at size 3) and failed within, or at the base of, the storm snow.
Snowpack Summary
The recent storm dropped anywhere from 40 cm to 1 m of snow at upper elevations, while rain soaked the snowpack below treeline. The freezing level was between 1700 m and 2400 m during the storm. Strong NW through SW winds have redistributed snow into wind slabs and created cornices at alpine elevations. Below the storm snow is a layer of buried surface hoar and/or a crust, which is increasing the reactivity of storm slabs. Deeper in the snowpack, a weak interface buried in mid-February is still on the radar. Although unlikely to be triggered, it remains possible with a very heavy load or from a thin-spot trigger point. A facet/crust layer sits at the base of the snowpack in some areas.As temperatures cool, wet slab/loose wet avalanche problems should improve, but persistent slab concerns at upper elevations will linger, especially on slopes which didnât avalanche during the storm.
Avalanche Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 6
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2 - 7
Wet Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Unlikely - Possible
Expected Size: 1 - 6