The upper snowpack will gain strength overnight, but watch for breaks in cloud cover to undermine slab and cornice stability on Sunday. Spring sunshine packs a punch.
Summary
Confidence
High -
Weather Forecast
Sunday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Freezing level to 1800 metres with alpine temperatures of -3Monday: A mix of sun and cloud with flurries beginning in the afternoon. Light southwest winds. Freezing level to 1700 metres with alpine temperatures of -4.Tuesday: A mix of sun and cloud. Light northwest winds. Freezing level to 1700 metres with alpine temperatures of -5.
Avalanche Summary
One 12-48 hour old Size 2.5 wind slab avalanche was reported on Friday. It occurred naturally on a steep, unsupported, north facing feature in the alpine.Several natural cornice falls up to size 3.5 were reported on Tuesday.
Snowpack Summary
Recent moderate to strong winds have been redistributing new snow from the past few days into wind slabs on a range of aspects in the alpine and at treeline. These new wind slabs have developed above a mix of old surfaces that include melt-freeze crusts below about 1900 metres and on solar aspects in the alpine. Below the new snow, a number of storm snow and crust layers that formed over mid to late March appear to be well bonded. The February weak layers are now down about 120-150 cm and the deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack. These deep weak layers produced large avalanches with cornice falls and other heavy triggers in late March and early April. They remain a concern and may be more likely to fail on southerly aspects during periods of strong solar radiation.
cgarritty,
Avalanche Canada
