Avalanche Forecast
Regions: Purcells.
Confidence
High -
Weather Forecast
Overnight: Cloud and moderate southeast winds developing with freezing down to 800 metres. Wednesday: 3-5 cm during the day with moderate southeast winds and daytime freezing up to 1600 metres. Thursday: 5-15 cm by morning, with the heaviest amounts in the south of the region. Daytime freezing up to 1800 metres. Friday: Another few cm of new snow with light winds and daytime freezing up to 1400 metres.
Avalanche Summary
Explosive control and natural triggers released cornices up to size 3.0 in the central part of the region on Monday. One cornice failed during explosives control when the shot was dropped onto the cornice structure resulting in a size 2.0 that did not release a slab on the slope below.
Snowpack Summary
Recent moderate to strong winds have redistributed new snow into wind slabs on a range of aspects at higher elevations. Fragile new cornice growth also occurred along ridgelines over the course of the week. The new snow has buried melt-freeze crusts on all aspects below about 2200 metres and in the high alpine on solar aspects. Isolated surface hoar may be found below the new snow on shaded aspects at high elevations. Below the new snow interface, a number of storm snow and crust layers that formed over mid to late March appear to be well bonded. At higher elevations, the February crust/facet layer is now down around 130-150 cm and the deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack. These layers were active during a storm in mid-March and produced some very large avalanches. Occasional deep releases were also reported in late March and early April, keeping these layers an ongoing concern.
Avalanche Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Cornices
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 2 - 3
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2 - 4