Avalanche Forecast
Issued: Feb 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Dry.
swerner,
Avalanche Canada
Up to 70 cm of storm snow has fallen since last weekend! Storm slab reactivity is expected to persist for longer than typical, due to the weak surface they are sitting on. Human triggering remains likely.
Summary
Confidence
Low
Avalanche Summary
No recent avalanche activity reported as of Tuesday morning.
On Sunday, a widespread natural cycle occurred throughout the region. Reports came in of very touchy human-triggered storm slabs (size 1-2) averaging 30-60 cm deep and up to 100 cm deep in wind-loaded areas.
Storm slab reactivity is expected to persist for longer than is typical due to the weak surface they are sitting on.
Check out last Friday's North Shore Snowpack Update for a picture of the unusual snowpack setup leading into last weekend's storm.
Snowpack Summary
Up to 20 cm of new snow overnight Monday adds to last weekend's storm snow bringing totals of 50-70 cm down to the valley bottom. This new snow has bonded poorly to the underlying surface formed by recent wind and cold temperatures. The old snow surface consists of weak faceted snow, old hard wind slabs, and a crust between 1100 and 1600 m.
The mid and lower snowpack is well-settled, strong, and consolidated.
Snowpack depths are reaching 250 cm at treeline.
Weather Summary
Tuesday Night
Clear periods. Treeline temperatures -4 °C. Ridge wind southeast 10-20 km/h. Freezing level valley bottom.
Wednesday
Cloudy with flurries, 5-10 cm of accumulation Treeline temperatures reach a high of -4 °C. Southwest wind 20 km/h and freezing level valley bottom.
Thursday
Snow amounts 10-20 cm. Ridgetop wind 35-55 km/h from the west. Treeline temperatures reach a high of -5 °C. Freezing level valley bottom.
Friday
Cloudy with sunny periods and isolated flurries. Treeline temperatures near -5 °C. Ridge wind southwest 40 km/h gusting to 70 km/h. Freezing level 500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
- Closely monitor how the new snow is bonding to the crust.
- Keep your guard up at lower elevations. Storms slabs have been reactive at all elevations.
- Avoid terrain traps where the consequence of any avalanche could be serious.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
Problems
Storm Slabs
Another 20 cm fell overnight Monday adding to last weekend's 50 cm of storm snow. The recent storm slab averaging 30-60 deep and up to 100 cm deep in wind-loaded areas may have bonded poorly to the underlying surface.
Storm slab reactivity is expected to persist for longer than is typical, particularly in areas where slabs are sitting on a weak layer of facets and/or a crust.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
If the recent storm snow lacks cohesion, dry loose avalanches will be likely from steep terrain features at all elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 1st, 2023 4:00PM
