Avalanche Forecast
Issued: Dec 18th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jleblanc,
Avalanche Canada
Strong outflow winds are expected to affect all elevations.
Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Summary
Confidence
Avalanche Summary
On Saturday, snowmobilers released several wind slabs accidentally, and some were remotely triggered. The failure plan is the December 6th surface hoar layer, buried down 20-50 cm. At lower elevations, a few wind slabs avalanches (size 1) were reported on lee features.
If you venture into the backcountry, please consider submitting a MIN report, as it helps to strengthen our data gathering.
Snowpack Summary
5-10 cm of fresh snow was received over the weekend. Surfaces at upper elevations are highly wind-affected and variable due to switching winds. In some parts of the region, a crust exists on south aspects. Dry snow still exists on northerly aspects at lower elevations.
A layer of large surface hoar crystals, buried in early December, is found down 20 to 50 cm. This layer has been producing small but remotely-triggered avalanches recently. Reverse-loading may increase the likelihood of triggering these slabs.
The lower snowpack is well consolidated above the mid-November crust, found at treeline below 1200 m.
Weather Summary
Arctic air has arrived, and the region will remain extremely cold through the end of the week. Strong outflow winds are expected through the coastal inlets and valleys.
Sunday night
Partly cloudy. Scattered flurries. Northeast wind 40 km/h at ridge tops. High of -20˚C.
Monday
Mainly sunny. No precipitation. Northeast wind 40 km/h at ridge tops. High of -22˚C.
Tuesday
Mainly sunny. No precipitation. Northeasterly wind 30 km/h at ridge tops. High of -24˚C.
Wednesday
A mix of sun and clouds. No precipitation. Northeasterly wind 45 km/h at ridge tops. High of -24˚C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be carefull around freshly wind loaded features.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Problems
Wind Slabs
Fresh slabs will likely form with northeasterly outflow winds and the recent snow. Winds slabs could overlie a weak layer of surface hoar, facets, and/or a crust. Any avalanche in the upper snowpack has the potential to scrub down to these deeper weak layers, making for larger-than-expected avalanches. This is especially relevant at treeline elevations, where surface hoar is more likely larger and better preserved.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 19th, 2022 4:00PM
