Avalanche Forecast
Issued: Feb 18th, 2022 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
Use caution at all elevations. The new snow likely won't bond well to the variety of surfaces it will fall on.
Summary
Confidence
Weather Forecast
Friday night: low of -3 at 1500m. light flurries bringing trace amounts of snow and moderate west winds.
Saturday: stormy with 10 to 20cm of snow and moderate west winds. High of -2 at 1500m.
Sunday: a mix of sun and clouds with light flurries bringing trace amounts of snow. Light northerly winds and a high of -3 at 1500m.
Monday: mostly sunny with a high of -8 at 1500m. Light north winds.
Avalanche Summary
On Thursday a natural icefall triggered a size 2.5 avalanche on the slope below. This avalanche was on a northeast aspect at 2100m.
On Wednesday one size one natural cornice fall was observed on a east aspect at 2200m. It was in extreme terrain and did not pull a slab on the slope below.
Snowpack Summary
New snow and westerly winds will likely form wind and storm slabs Throughout the day on Saturday.
The mid February crust is down around 10cm. This melt-freeze crust is reported to exist on all aspects and elevations except for some of the highest elevation polar aspects. Facets have been observed above the crust on polar aspects.
The late-January crust/facet/surface hoar interface is buried down 30-70 cm. This layer was most reactive between 1700 m and 2000 m. While this layer now appears to be dormant in many parts of the region, recent snowpack tests suggest it is still very reactive in a few places and would still be capable of producing large avalanches if triggered.
Terrain and Travel
- Watch for fresh storm slabs building throughout the day.
- Closely monitor how the new snow is bonding to the crust.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
Problems
Storm Slabs
Up to 20cm of new snow accompanied by westerly winds will likely form wind and storm slabs throughout the day on Saturday. These slabs could be touchy on north aspects where they will form on facets over a crust. Use extra caution near ridge crests and steep roll overs where wind slab is more likely to be found.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The late-January weak layer is down 30-70 cm and was most reactive between 1700 and 2000 m. It is now likely dormant in many areas, especially where there is a supportive surface crust. However, recent snowpack tests suggest it is still reactive and capable of producing large avalanches if triggered. We have now entered a low probability, high consequence scenario with this layer.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 19th, 2022 4:00PM
