6:45 AM Update:
New snow and strong winds are overloading weak layers in the snowpack, creating very dangerous conditions
If you see less than 25 cm of new snow, the danger is CONSIDERABLE
Three reactive, problematic persistent weak layers exist in the upper 150 cm of the snowpack. These layers continue to surprise people with instances of remote triggering and releasing on low angle slopes in unexpected areas.
New snow and strong southerly winds are building reactive new storm slabs. Avoid alpine avalanche terrain today.
Numerous natural and human-triggered wind slab and persistent slab avalanches have been occurring daily. Some of them are being triggered accidentally or remotely and are occurring on all aspects and elevations. Many of these avalanches failed on persistent weak layers, including a serious incident in the Selkirks on Thursday.
Reactivity on the weak layers is expected to continue, and both natural and human-triggered avalanches may be possible.
Up to 10 cm of new snow may have fallen by Monday morning. Strong southerly winds may build fresh wind slabs near ridgetops throughout the day.
Three persistent layers of concern may be found in the upper 150 cm of the snowpack:
25 to 60+ cm down is a layer of surface hoar in sheltered areas, or a melt-freeze crust on sun-exposed slopes from mid-February.
40 to 100+ cm down is the early-February layer of surface hoar in wind-sheltered terrain and a crust on sun-exposed slopes.
70 to 120 cm down is the late-January layer of surface hoar and facets over a melt-freeze crust.
All of these persistent layers continue to cause large avalanches in the region.
The remainder of the snowpack is strong.
Sunday Night
Cloudy. 3 to 5 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Monday
Cloudy. 10 to 15 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -6 °C.
Tuesday
Mostly cloudy. 4 to 10 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -8 °C.
Wednesday
Mix of sun and clouds. 3 to 10 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -8 °C.
More details can be found in the Mountain Weather Forecast.
