Avalanche Forecast
Issued: Mar 18th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs.
mconlan,
Avalanche Canada
A cool, cloudy day is forecast for Thursday. Still apply caution when travelling near thin, rocky start zones.
Summary
Confidence
High - Confidence is due to a stable weather pattern with little change expected.
Weather Forecast
WEDNESDAY NIGHT: Cloudy, light north wind, alpine temperature -10 C.
THURSDAY: Cloudy, light northwest wind, alpine temperature -12 C.
FRIDAY: Clear skies, light to moderate northwest wind, alpine temperature -5 C, freezing level 1500 m.
SATURDAY: Clear skies, light northwest wind, alpine temperature -3 C, freezing level 1800 m.
Avalanche Summary
On Tuesday, explosives triggered small wind slabs, which stepped down to the faceted grains over the melt-freeze crust described in the snowpack summary. The avalanches were generally on west aspects and were large (up to size 2.5). The likelihood of similar avalanches on Thursday will decrease with cool, cloudy weather forecast.
If you decide to travel in the backcountry, consider sharing your observations with us and fellow recreationists via the Mountain Information Network (MIN) to supplement our data stream as operators are shutting down. Even just a photo of what the day looked like would be helpful.
Snowpack Summary
Sunny skies have formed a melt-freeze crust on sun-exposed slopes. The alpine consists of wind affected snow from easterly wind. This wind direction is atypical, so you may find small pockets of wind slabs in terrain features on south to west aspects.
A layer of faceted grains overly a melt-freeze crust from early February. This layer currently sits 40 to 80 cm below the surface.Â
The base of the snowpack contains basal facets that are most prominent in shallow, rocky start zones.
Terrain and Travel
- Carefully evaluate steep lines for wind slabs.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
- Be aware of the potential for large avalanches due to the presence of a deep persistent slab.
Problems
Deep Persistent Slabs
Weak snow at the bottom of the snowpack hasn't gone away. Evidence of deep persistent slab avalanches has been focused in the Sparwood-Elkford area over the past month. Human triggering is most likely around steep, rocky terrain features or anywhere the snowpack is thin and weak. A failing cornice could initiate a deep persistent slab when it impacts the slope below.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 19th, 2020 5:00PM
