Avalanche Forecast

Low - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Wednesday night: stormy weather with moderate to strong west winds. up to 5cm of snow. Low of - 10 at 1500m.

Thursday: stormy weather continues with 5cm of snow. Moderate west winds becoming southwest in the evening. High of -4 at 1500m. 

Friday: stormy with up to 15cm of snow. Strong southwest winds with extreme gusts. Freezing levels rising to 1400m.

Saturday: some light flurries with moderate northwest winds. High of -2 at 1500m.

On Tuesday in the north of the region one skier remote size one was reported. This avalanche was on a northeast aspect at 1700m and is believed to have failed on the surface hoar and facet layer down 30cm from late January.

On Tuesday, there was a report of a small (size 1) human-triggered avalanche that released in the recent snow on a convex feature at upper treeline elevations near Pemberton. 

In the neighbouring Sea to Sky region, we received a report of a large (size 2.5) human-triggered avalanche near Rainbow Mountain that caught and carried a group of five skiers. The avalanche released on north aspect at 1900 m. It broke 40 cm deep on the late January facet-crust layer. The avalanche propagated across adjacent roll-over features and triggered a sympathetic slide on a small feature 200 m away.

On Sunday, observers in the north of the region reported large (size 2) natural avalanches releasing in the storm snow near Dark Side Lake (see this MIN and this MIN).

New snow and west winds will add to the 15-30 cm of snow above 1400 m near the Duffey and above 1700 m near the Coquihalla that arrived over the weekend. Strong southwest winds during the storm have since become moderate from the northwest and have redistributed the recent snow into wind slabs across a range of aspects at upper elevations. Monitor for changing slab conditions as you move into wind-exposed terrain.

Recent snow rests on a problematic layer combination. Weak sugary facets formed during a prolonged dry period over a thick melt-freeze crust. In sheltered areas at upper elevations, surface hoar may also be found on the crust. This late January facet-crust layer has demonstrated continuing reactivity in the aftermath of the weekend storm, particularly in the northern half of the region. Travellers have reported remote-triggered avalanche activity and widespread whumpfing on this layer (see this MIN report and this MIN report from Joffre Peak). In the south near the Coquihalla, this layer combination is likely specific to colder aspects at upper elevations where the facets were preserved. 

Deeper in the snowpack, it is possible to find a crust/facet layer from December that is buried down 100-150 cm. This layer is most prominent between 1700-2100 m and is currently classified as dormant; although large loads such as a cornice failure or avalanches in motion may still be able to trigger avalanches on this layer.

• Recent wind has varied in direction so watch for wind slabs on all aspects.
• Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
• Be aware of the potential for large avalanches due to the presence of buried weak layers.
• Remote triggering is a concern, avoid terrain where triggering slopes from below is possible
• Extra caution is needed around cornices under the current conditions.