Avalanche Forecast
Issued: Dec 24th, 2018 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
shorton,
Avalanche Canada
The persistent slab problem is best managed with patience and conservative terrain choices. Read more in the new forecaster blog here.
Summary
Confidence
High - The weather pattern is stable
Weather Forecast
MONDAY NIGHT: Cloudy with clear periods, light wind, alpine temperature drop to -10 C.TUESDAY: Mix of sun and cloud, light wind, alpine high temperatures around -10 C.WEDNESDAY: Mostly cloudy, light wind, alpine high temperatures around -10 C.THURSDAY: Mix of sun and cloud, light wind with moderate gusts from the northwest, alpine high temperatures around -10 C.
Avalanche Summary
The most recent 10-30 cm of low density snow was reactive to skiers on steep and convex features on Sunday. Otherwise, natural and human triggered activity has started to tapered off.However, as recent as last Friday, large (size 2-3) persistent slab avalanches were occurring naturally. There have also been a few notable persistent slab avalanches remotely triggered from skiers on adjacent slopes. Most recently, last Wednesday a few large (size 2-2.5) avalanches on north-facing slopes were remotely triggered by skiers in the Selkirks.
Snowpack Summary
10-20 cm of low density snow sits above wind slabs in the alpine, and in some isolated areas above small surface hoar (feathery crystals).A weak layer that formed during the dry spell in early December is now 50-100 cm deep. The layer is composed of weak facets, surface hoar, and a sun crust on steep south-facing slopes. This layer has been responsible for large persistent slab avalanches over the past two weeks, particularly on north and east facing slopes between 1900-2300 m and on steep south-facing slopes in the alpine.The lower snowpack is generally strong and settled, with a crust that formed in late October near the bottom of the snowpack.
Problems
Persistent Slabs
The likelihood of persistent slab avalanches is gradually decreasing, but triggering a widespread weak layer buried 50-100 cm beneath the surface has major consequences. This problem will likely linger through the holidays.
Minimize exposure to steep, planar, south-facing alpine slopesUse caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 25th, 2018 2:00PM
