Maintain conservative terrain selection as we transition out of the storm. Watch for periods of sun to destabilize sun-exposed slopes.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
Monday: A mix of sun and cloud. Light southeast winds. Alpine high temperatures around -11.Tuesday: A mix of sun and cloud. Light southwest winds. Alpine high temperatures around -10.Wednesday: Cloudy with light flurries beginning in the afternoon and continuing overnight. Light southeast winds. Alpine high temperatures around -6.
Avalanche Summary
Reports from Saturday included two more natural slab avalanches. A size 1.5 storm slab failed on a south aspect at 2300 metres while another deeper size 2.5 slab released from a very steep north aspect at 2700 metres. Their respective crown fracture depths were 80 cm and 200 cm and the failure plane of the deeper release is not certain.On Friday, a natural size 2.5 storm slab avalanche was reported west of Valemount on a northwest aspect at 2400 m.On Thursday, a few size 2 natural storm slab avalanches were reported on north and east aspects. A cornice fall triggered a large slab avalanche with a 100 cm crown on a north aspect at 2600 m. A skier also remotely triggered a size 1 wind slab on a southeast aspect at 1900 m.These avalanches follow a widespread natural avalanche cycle that occurred on Tuesday and Wednesday. Storm slabs in the size 2-3 range were reported on all aspects between 1700 and 2500 m. Southerly aspects were the most reactive with numerous large and very large (size 2.5-3.5) avalanches running on the recently buried sun crust.
Snowpack Summary
Another 20-30 cm of new snow on Friday brought last week's total to 60-100 cm. Storm snow was accompanied with strong west wind, forming reactive slabs at higher elevations.The storm snow sits on an interface buried in late-March that consist of crusts at low elevations and on south aspects, and surface hoar on shaded aspects at higher elevations.Persistent weak layers from early January and mid-December are still being reported by local operators, but are generally considered dormant.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.