Avalanche Forecast
Issued: Feb 12th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Carefully evaluate steep features at ridgecrest for lingering wind slabs and cornice hazards before committing to your line.
Summary
Confidence
Weather Forecast
Wednesday night: Clear periods. Light west winds, increasing into the morning.
Thursday: Becoming cloudy with light flurries beginning late afternoon. Moderate to strong southwest winds. Alpine high temperatures around -5 with freezing levels rising to around 1300 metres.
Friday: Mainly cloudy with continuing light flurries and up to 5 cm of new snow - 10-15 cm including the overnight period. Light to moderate southwest winds, increasing overnight. Alpine high temperatures around -7.
Saturday: Cloudy with scattered flurries bringing up to 5 cm of new snow, easing overnight. Moderate southwest winds, becoming strong at ridgetop, easing overnight. Alpine high temperatures around -6.
Avalanche Summary
New avalanche observations from Tuesday were limited to a few small (size 1) wind slabs able to be skier triggered in crossloaded gully features. Observations into the alpine were limited by poor visibility.
On Monday control work produced a cornice failure from a northeast facing ridge, a couple of size 2 wind slabs on a northwest facing feature at 2000 m and small stubborn wind slabs to size 1.
On Sunday no new natural avalanches were reported but smaller wind slab avalanches to size 1.5 were human triggered on northeast facing features around 1900 m with an average depth of 25 cm.
On Saturday storm slab avalanches to size 2 were widespread. They ran naturally and were intentionally triggered by avalanche control work on all aspects.
Fragile cornices and one large cornice fall have been reported over the past 10 days.
Snowpack Summary
The weekend storm produced 15 to 25 cm of warm storm snow. This snow has been formed into slabs in wind exposed terrain by previously strong winds that were largely out of the northeast. This snow rests on previously wind affected snow and a thick rain crust that exists up to roughly 2100 m. In many areas this capping crust extends to mountaintops.
Sheltered areas now have 15-30 cm of snow above the crust. The bottom 20 cm of the snowpack consists of basal facets and decomposing crusts that have not been an active avalanche problem since December, but could reemerge as a problem after sustained warming.
Terrain and Travel
- Caution around slopes that are exposed to cornices overhead.
- Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
Problems
Wind Slabs
Wind slabs that formed above our widespread crust are growing resistant to human triggering as they age but could still be a problem in steep terrain immediately lee of ridge crest as well as on bigger, more extreme terrain features.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 13th, 2020 5:00PM
