Avalanche Forecast
Issued: Mar 7th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
cgarritty,
Avalanche Canada
Start small and watch for signs of instability or indications that new snow has settled into a reactive slab over the old snow surface on Sunday. Expect new snow to become especially touchy on southerly slopes if the sun makes an appearance.
Summary
Confidence
Weather Forecast
Saturday night: Cloudy with continuing flurries bringing 5-10 cm of new snow. Moderate southwest winds.
Sunday: Mainly cloudy with isolated flurries and a trace of new snow. Moderate to strong southwest winds. Alpine high temperatures around -9.
Monday: Sunny. Light southwest winds. Alpine high temperatures around -8.
Tuesday: Mainly sunny in the morning with cloud increasing over the day. Moderate to strong southwest winds. Alpine high temperatures around -4.
Avalanche Summary
Preliminary reports from Saturday mainly show new snow reacting to skier traffic and explosives control as dry loose sluffs, reaching size 2. Soft slab formation was noted in wind-affected features at ridgecrest.
Elevated avalanche danger is expected to be maintained through Sunday as the new snow settles into more consolidated storm slabs that only gradually begin bonding with the previous snow surface. Periods of sunshine may also promote natural avalanche activity.
Snowpack Summary
By the time snowfall eases off Saturday night, new snow totals over the region may reach up to 30 cm. The new snow has buried heavily wind affected surfaces in exposed areas as well as sun crust on solar aspects and temperature crusts up to 1700 m on all other aspects. The new snow is not expected to bond well with any of these surfaces over the short term.
A thick rain crust that has facets associated with it sits 30-60 cm below the surface and can be found up to ridgetops. We have only seen one avalanche on this layer since February 17th. The mid-pack is well settled and strong, but the base of the snowpack contains basal facets that are most prominent in shallow rocky start zones.
Terrain and Travel
- Use increased caution at all elevations. Storm snow is forming touchy slabs.
- Make conservative terrain choices and avoid overhead hazard.
Problems
Storm Slabs
20-30 cm of new snow is settling into storm slabs that are not expected to bond well with the previous snow surface. Wind has already been observed accelerating slab formation around ridgetop features. Snow may shed naturally as slabs or dry loose releases from slopes exposed to sunshine.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices have grown large and loom over many ridge lines. They have potential to fail naturally as well as under the weight of a person or machine and they may trigger slabs on slopes below them. Give them a wide berth.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 8th, 2020 5:00PM
