Sunday night's storm will layer new surface instabilities over an otherwise stable snowpack. Tune into new snow amounts, wind loading, and daytime warming to stay on top of the hazard.
New snow and wind should form reactive slabs to manage on Monday. Slab size and distribution will mainly be of consequence where more than 10 cm of new snow accumulates.
Increasing solar radiation will promote new snow shedding from solar slopes on Monday. This will mainly be a problem where more than 10 cm of new snow accumulates.
There were only a couple of small avalanches in the Fernie area in the past few days. One was a 30 cm-deep skier-triggered storm slab on a north aspect and the other a small cornice failure that triggered a size 1 storm slab below an alpine ridgetop. Both occurred on Friday at 2100 m or higher and ran on the late-March crust. New snow followed by sunshine should revive surface instabilities for Monday.
If you are heading into the backcountry, post a MIN!
5-10 cm of forecast snow (closer to 15 cm in the north of the region) will bury melt-freeze crust now found on solar aspects, or otherwise add to 10 to 20 cm of recent snow, previously affected by previous southwest wind. Reactive new slabs should form with the new snow, predominantly where snowfall is greatest.
The recent snow sits on a thick crust. Below it, up to 50 cm of rain soaked snow sits on another crust (1 to 10 cm thick) from early March.
Persistent weak layers may linger within the top 150 cm of the snowpack. These are unlikely to trigger in most areas as a result of the thick crust bridging over them.
The mid and lower snowpack is strong in most areas. Snowpack depth tapers rapidly at lower elevations.
Sunday Night
Cloudy with continuing flurries bringing 5 to 10 cm of snow, closer to 15 cm in parts of the north of the region. 30 to 50 km/h southwest ridgetop wind, easing. Treeline temperature falling to -6 °C.
Monday
A mix of sun and cloud with isolated flurries and a trace of new snow. 20 km/h west ridgetop wind. Treeline temperature -7 °C.
Tuesday
Sunny. 10 km/h south ridgetop wind. Treeline temperature reaching -2 °C as freezing level climbs to 1800 m.
Wednesday
Initially sunny, becoming floudy with light flurries at end of day. 20 km/h south ridgetop wind. Treeline temperature -1 °C with freezing level to 1900 m.
More details can be found in the Mountain Weather Forecast.
