Avalanche Forecast
Issued: Nov 24th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Dry.
LP,
Avalanche Canada
Snow Incoming! Expect the hazard to build to Considerable through Friday in the areas that receive higher snow amounts. Early season conditions persist with lots of variability in snow depth. The many lurking hazards may become hidden with the fresh snow.
Summary
Confidence
Moderate
Avalanche Summary
A notable size 2 wind slab was remotely triggered yesterday on a lee alpine feature on a South aspect on Observation Sub Peak. It had impressive propagation on the underlying weak facets and scrubbed to the ground. Lake Louise patrol triggered several wind slabs size 1-2 with explosives and ski cuts over the past week and noticed increased sensitivity through the week.
Snowpack Summary
On Thursday, strong to extreme SW winds scrubbed the alpine and treeline and freezing levels climbed to 2200 m or higher on South facing terrain. Otherwise, the snowpack is thin with a breakable sun crust on steep south aspects and weak facets on north aspects. 40-70 cm of total snow at treeline throughout the region, with up to 120 cm in loaded alpine features.
Weather Summary
Expect flurries on Friday as a cold front descends across the region with 5-20 cm expected (greater amounts occurring along the continental divide and in Little Yoho). Strong SW winds will accompany the snow and ease with the passage of the front bringing cooler, more seasonable temperatures.
For Saturday, light flurries are forecast through the day, and then another cold front crosses the region Sunday morning with more snow.
For more information specific to the forecast region, see https://www.avalanche.ca/weather/forecast
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for areas of hard wind slab on alpine features.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
Problems
Wind Slabs
Incoming snow and wind on Friday will further add to this problem and may hide existing wind slabs. Recent strong SW winds have created small, hard, wind slabs on the lees of features. These sit on a weak facetted base. If triggered, depending on the feature, you may see wide propagations and expect entrainment of the facets in the track causing the avalanche to run further than expected.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Areas that receive greater snow amounts may see a building loose dry problem through the day Friday, especially with the accompanying wind. If triggered, the avalanche may gain mass by entraining the thin weak facetted snowpack. This will primarily be a problem in steep gullied terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 26th, 2022 4:00PM
