Summary
Confidence
Fair - Timing of incoming weather is uncertain on Friday
Weather Forecast
Friday: Light snow, becoming moderate to heavy by Friday afternoon. Expect enhanced snow fall in the west and less further east. Freezing level may slowly rise by afternoon. Winds increasing to strong westerlies by afternoon.Saturday: Moderate to heavy snow continuing (again, drier further east). Freezing level rising briefly to around 1000m on Saturday morning. Westerly winds.Sunday: Light snow. Freezing level valley floor.
Avalanche Summary
Skiers easily triggered size 1 slabs in both the Flathead and South of Crowsnest regions on Thursday. In the Flathead, these were running on a crust/facet/surface hoar combo below the storm snow (about 50-60cm deep). A skier remotely triggered a size 1 slab on a NE aspect at 2300m from 20m away. A widespread natural avalanche cycle occurred in the Elk Valley on Tuesday/ Tuesday night, with numerous slabs up to size 3 releasing in the alpine on mainly east-facing slopes. Initial reports suggest that these released up to 2m deep on wind-loaded slopes. South of the Crowsnest, a few size 1-2 slabs were reported during the storm.
Snowpack Summary
40-60cm recent snow has formed soft slabs over a crust/facet/surface hoar combo. In sheltered areas, fast-moving sluffs also remain a concern. Forecast warming on late Friday/Saturday likely to create a more widespread storm slab problem.Deeper in the snowpack, a surface hoar layer buried in early December remains a concern, as avalanches triggered on this layer would be destructive. However, information is limited about its current reactivity. From preliminary observations, the rapid storm snow load on Tuesday did not cause any releases on this layer. Facets sandwiched between two firm layers in the top metre of the snowpack are being monitored in the south-east.
pgoddard,
Avalanche Canada
