Avalanche Forecast
Regions: Bull, Elkford East, Elkford West, Flathead, Lizard, Lizard-Flathead, South Rockies.
The impact of recent wind was extensive and left unstable wind slabs in alpine and treeline terrain.
Confidence
Moderate
Avalanche Summary
Several skier-triggered wind slab avalanches were reported in the Fernie area on Friday. They were size 1 to 2, occurring in both alpine and open forested terrain, as illustrated in MIN reports here, here, and here. Earlier in the week, there were several natural and explosive triggered storm and wind slab avalanches.
Wind slab avalanches will continue to be possible to trigger at upper elevations throughout the region and deep persistent slab avalanches should be on your radar in the Elkford and Flathead areas.
Snowpack Summary
Wind-affected snow is fairly extensive, with wind slabs reported into sparsely forested terrain at treeline. 10 to 30 cm of soft snow from earlier this week can be found in wind-sheltered terrain. The snow overlies old wind slabs, or a melt-freeze crust below 1900 m.
In the Lizard range specifically, the mid-pack is consolidated with a supportive 10 to 20 cm thick frozen crust buried 80 to 100 cm.
In the Elkford and Flathead areas, deeply buried weak layers are slowly gaining strength but are still a concern, especially in steep rocky terrain features where the snowpack is thin.
Weather Summary
Saturday night
Partly cloudy, no precipitation, 30 to 40 km/h west wind, treeline temperatures drop to -8 ºC.
Sunday
Sunny periods in the morning then increasing cloud in the afternoon, no precipitation, 40 to 50 km/h southwest wind, treeline temperatures to -4 °C with freezing level climbing to 1500 m.
MondayFlurries with 10 to 15 cm of new snow, 50 to 70 km/h southwest wind, treeline temperatures to -4 °C with freezing level climbing to 1500 m.
TuesdayMix of sun and cloud, no significant precipitation, 20 km/h north wind, treeline temperatures drop to -10 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind affected terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Avalanche Problems
Wind Slabs
Widespread wind slabs have been reported in alpine and treeline terrain. Several large avalanches were triggered on Friday, and will continue to be possible to trigger in steep wind-affected terrain.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Deep Persistent Slabs
A layer of faceted grains near the base of the snowpack remains on the radar for areas of this region where the snowpack is shallow and where a hard melt-freeze crust formed around Christmas doesn't exist (Elk Valley and Flathead range). Deep persistent slab avalanches have not been reported in the region for some time, however, the weak snowpack structure in these shallow areas may still be triggered with a heavy load.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2.5 - 3.5