Avalanche Forecast
Issued: Dec 5th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
Parks Canada,
Avalanche Canada
One more day of clear skies and warm temperatures on Friday, with freezing levels up to 1900 m triggering loose wet avalanches into gullies. Ice climbers avoid south-facing terrain. Conditions change starting Friday night with extreme winds, then a storm day on Saturday with snow and rain throughout the day.
Summary
Confidence
Moderate
Avalanche Summary
Observations from across the park on Thursday of avalanches up to size 2 releasing on sunny exposures, both in the ski areas and backcountry. The common theme is moist snow releasing a small slab, then gouging down to facets and running further than expected. Lake Louise got one explosive-triggered avalanche in a steep N aspect, failing on the Nov 9 layer 40 cm above the ground.
Snowpack Summary
Two warm and clear days have left the snow surface a mix of wet snow, suncrust, wind crust and facets. This overlies a mostly faceted snowpack 40-90 cm deep with two weak layers near the base (Oct 20 and Nov 9 crusts). These crusts continue to produce isolated avalanches. No new snow is expected on Friday, but by Saturday expect new snow and wind to create easily triggered surface slabs, some may fail on the ground.
Weather Summary
Some active weather is coming our way as a warm Atmospheric River comes onto the coast of BC and spills over into Alberta starting Friday night and all day on Saturday. Expect extreme winds (>100 km/hr) on Friday night, rain and snow through Saturday and freezing levels to 1900 m, then clearing and cooling on Sunday as the system exits the region.
Terrain and Travel Advice
- Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches.
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
- Be mindful that deep instabilities are still present in the snowpack.
Problems
Deep Persistent Slabs
The October and November crusts, on north and south aspects respectively, are still producing isolated slab avalanches down about 50-80 cm. Be mindful on steep, rocky alpine slopes where triggering is most likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Recent moderate to strong winds have formed wind slabs on lee slopes in the alpine. If triggered, these slabs could entrain facets, leading to longer-than-expected runouts.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 6th, 2024 4:00PM
