Avalanche Forecast
Issued: Feb 12th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
trettie,
Avalanche Canada
Continue to make conservative terrain choices. Storm slabs will likely still be reactive to rider traffic.
Summary
Confidence
Moderate
Avalanche Summary
We suspect that a large natural avalanche cycle has taken place during the day on Sunday.
On Wednesday, skiers triggered a large, size 2, avalanche near Ningunsaw. The Deep Persistent avalanche was triggered on an east aspect near ridgetop in a thin, rocky start zone and failed on basal facets.
Snowpack Summary
Up to 100cm of storm snow overlies older wind-affected surfaces and a supportive melt-freeze crust up to 1800 m and steep solar slopes. South-southwesterly winds have been scouring and pressing southerly slopes and wind slabs on northerly aspects. Large cornices are also being reported on many northerly aspects.
100 to 200cm of storm snow from the past two weeks is settling over a layer of facets, crust, and previous wind-affected surfaces in alpine terrain. We're continuing to track this layer given recent avalanches on this interface under the patterns of continuous loading and successive natural avalanche cycles.
The mid and lower snowpack continues to bond and stabilize while a number of buried weak layers are still being tracked by professionals in the region, having produced a few large avalanches in the not-too-distant past.
Weather Summary
Sunday Night
Stormy with 10 to 30cm of new snow expected. Moderate southwest winds and a low of -4 at 1500m.
Monday
Cloudy with up to 5cm of new snow expected. Light to moderate northwest winds and temperatures at 1500m falling throughout the day to -11.
Tuesday
A mix of sun and cloud with flurries in the afternoon bringing a few centimeters of new snow. Light southwest winds and a high of -8 at 1500m.
Wednesday
Cloudy with up to 10cm of new snow expected. Moderate southwest winds and a high of -6 at 1500m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Avoid exposure to slopes that have cornices overhead.
Problems
Storm Slabs
Storm slabs will likely remain sensitive to rider traffic. avoid wind loaded slopes near ridge crests where slabs are likely to be largest and most reactive.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A deeply buried weak layer still presents a Low Probability/High Consequence situation. New snow and wind has been testing this weakness in the snowpack and the results still aren't in. This layer would be most likely to be triggered in places where the snowpack is shallow and rocky.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 13th, 2023 4:00PM
