Avalanche Forecast
Issued: Dec 20th, 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 continue to affect all elevations.
Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Summary
Confidence
Avalanche Summary
No avalanches have been reported in these areas. If you venture into the backcountry, please consider submitting a MIN report, as it helps to strengthen our data gathering.
Snowpack Summary
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. Now-faceted snow still exists in protected areas 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. Continued reverse-loading is increasing 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
The same story continues with the bitterly cold arctic air mass over the region. Gusty outflow winds through the coastal inlets and extremely cold temperatures are expected to persist through Thursday night. An abrupt change in the weather pattern is expected for the weekend.
Tuesday night
Mainly sunny. No precipitation. Northeasterly wind 30 km/h at ridge tops. Low of -24˚C.
Wednesday
A mix of sun and clouds. No precipitation. Northeasterly wind 45 km/h at ridge tops. High of -24˚C.
Thursday
Mostly cloudy. Isolated flurries. Northeasterly wind 20 km/h at ridge tops. High of -20˚C.
Friday
Snow 15-20 cm. Southwesterly wind 50 km/h at ridge tops. High of -18˚C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be carefull around freshly wind loaded features.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
Problems
Wind Slabs
Wind slabs exist in the alpine and open areas at treeline elevations due to reverse loading created by strong outflow winds. 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 21st, 2022 4:00PM
