Avalanche Forecast
Issued: Dec 25th, 2018 3:42PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
ghelgeson,
Avalanche Canada
We're into a week of stable weather, but a persistent slab problem still warrants relatively conservative terrain choices. Read more in the new forecaster blog here.
Summary
Confidence
Moderate -
Weather Forecast
The BC weather will take a holiday break over the next couple of days as the wild storm cycle of recent weeks eases in the Pacific.CHRISTMAS NIGHT: Freezing level at valley bottom, light southerly wind, no significant precipitation expected. BOXING DAY: Overcast, freezing level at valley bottom, light southerly wind, trace of snow possible. THURSDAY: Broken cloud cover, freezing level at valley bottom, light northerly wind, no significant precipitation expected. FRIDAY: Scattered cloud cover, freezing level at valley bottom, light southerly wind with potential for moderate gusts late in the day at upper elevation, trace of snow possible.
Avalanche Summary
On Monday riders triggered small loose dry avalanches in steep terrain as the storm snow sluffed away. A brief appearance of the sun also induced small loose dry avalanches.A few small dry loose avalanches and wind slabs were reported in the most recent snow on Sunday. On Saturday, a few large (size 3) avalanches were triggered by explosives on south-facing alpine slopes. The avalanches released on persistent weak layers 60-150 cm deep. Otherwise, natural and human triggered activity has started to tapered off.Over the past week, several notable persistent slab avalanches have been remotely triggered from skiers on adjacent slopes, particularly in the Selkirks and the northern tip of the Monashees. The most recent occurred in the Selkirks on Friday, where a size 2.5 slab on a south slope at 2200 m was remotely triggered from low angle trees.
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 80-120 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 northeast 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 80 to 120 cm beneath the surface would have major consequences. This problem will likely linger through the holidays.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.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.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2018 2:00PM
