Avalanche Forecast
Regions: Purcells.
Confidence
Moderate - Freezing levels are uncertain on Wednesday
Weather Forecast
TUESDAY and WEDNESDAY: Mainly sunny and dry with isolated valley cloud dissipating throughout the day. Freezing levels reaching 1500m and light variable winds. THURSDAY: Mainly sunny and dry with isolated valley cloud dissipating throughout the day. A temperature inversion is expected to result in above freezing temperatures well into alpine elevations Winds should remain generally light from the south.
Avalanche Summary
Reports from Sunday include a natural Size 2 persistent slab avalanche and a Size 2.5 cornice failure. Several Size 1 skier-triggered wind slabs were also reported and explosives control produced slab avalanches up to Size 3. On Saturday one person was killed and another was hospitalized in a large avalanche in the Quartz Creek area west of Golden. This size 3 snowmobile-triggered slab avalanche occurred on a S-SW aspect in the alpine and is suspected to have released on the Feb. 12 interface.
Snowpack Summary
20-30 cm of snow in the past few days has added to the recent storm slab bonding reasonably well to a crust 40-60 cm below the surface, that was buried on February 12th. However, in isolated areas (such as shady sheltered treeline slopes) there may be a weak layer of surface hoar at the storm snow/crust interface that is touchy to human triggers and may result in wide propagations. The early January surface hoar/ facet layer is typically down 70-120 cm. Avalanche activity at this interface has tapered-off over the past week, but I'd be reluctant to trust this potentially destructive layer just yet. In general, the lower snowpack is well settled and strong, apart from some thin snowpack areas where basal facets exist.
Avalanche Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 4
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 3
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 4