Avalanche Forecast
Issued: Nov 30th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
CB,
Avalanche Canada
Rider triggering of the Nov 17 persistent weak layer is possible. Pay attention to signs of instability, including whumphing, cracking and settlements.
Snowpack variability and limited observations are making forecasting danger challenging, please post a MIN with any relevant observation from your backcountry travel.
Summary
Confidence
Low
Avalanche Summary
Few natural avalanche avalanches have been observed along the highway corridor in the last 3 days.
One MIN report of 'whumpfing' and remote triggering several avalanches up to size 1.5, ~50cm deep, on moraine features below Glacier Crest on Monday. A Parks Canada field team experienced widespread 'whumpfing' at treeline and below in the Fidelity area on Monday as well.
Snowpack Summary
5-10 cm of fresh storm snow on Wednesday with light winds. This overlies wind slabs in alpine and treeline lee features built by strong SW winds. The Nov 17 persistent slab (surface hoar 5-30mm, facets, and crust) is down 70-90cm with the largest surface hoar present at treeline and below.
The early season hazards are slowly being buried but remain a concern. The height of snow at treeline is ~140cm.
Weather Summary
As a storm exits the region Thursday morning, isolated flurries linger and cold temperatures return through Saturday.
Thursday expect a mix of sun and cloud, possible flurries, an Alpine high of -14*C, light NW ridge-top winds.
Fri/Sat isolated flurries are forecast with mod to light SW ridge top winds and Alpine highs of -15*C.
More details can be found in the Mountain Weather Forecast.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Recent new snow may be hiding windslabs that were easily visible before the snow fell.
Problems
Persistent Slabs
The Nov 17 surface hoar, facets and crust is now buried by 50-80cm of snow and has been reactive on convex rolls and steep open slopes. Investigate smaller adjacent slopes before stepping out into bigger terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Wind slabs created on the weekend are slowly gaining strength. Watch of hard deposits of snow in the alpine and open areas at treeline formed by strong SW winds.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 1st, 2022 4:00PM
