Recent snow combined with sun and warm conditions on Monday will create unstable conditions.
Travel in complex avalanche terrain is not recommended.
A persistent weak layer of surface hoar or facets remain a concern in the upper 50 to 90 cm of the snowpack. Storm slabs in motion or cornice failures could step down to this layer causing larger than expected avalanches.
Storm slabs are expected to remain reactive on Monday, especially with high freezing levels and sun in the forecast.
Wet loose avalanches will be likely during periods of sun or when the snow surface is moist or wet. Avoid overhead hazard from steep sunny slopes.
On Friday, a large (size 2) naturally-triggered persistent slab failed on a north-facing alpine slope near Crescent Spur. Several naturally triggered wind slabs have been reported in the region over the past few days, with some triggered by collapsing cornices. They were generally in the size 1-2 range (small to large). Whumpfing and shooting cracks were also reported by skiers near McBride - see this great MIN for details.
15 to 30 cm of new snow has accumulated since Sunday, building reactive storm slabs. Sun and warming on Monday are expected to make the new snow particularly unstable. Sunny slopes and lower elevations will have moist or wet snow. The early March crust / surface hoar persistent weak layer is down 50 to 90 cm. The greatest concern for this layer is on sheltered north and east-facing upper-elevation terrain. Another weak layer of facets or surface hoar from mid-February lies 70 to 100 cm deep. This layer appears to be strengthening and has not triggered any recent avalanches. The lower snowpack remains well-settled.
Sunday Night
Cloudy with 5 to 15 cm of snow / possible rain below 1000 m. 30 to 45 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level around 1400 m.
Monday
A mix of sun and cloud. 45 km/h west ridgetop winds. Treeline temperature -1 °C. Freezing level rising to 1600 m.
Tuesday
A mix of sun and cloud. 15 to 30 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1700 m.
Wednesday
Cloudy with 1 to 5 cm of snow / possible rain below 1600 m. 35 to 40 km/h southeast ridgetop wind. Treeline temperature +1 °C. Freezing level rising to 1900 m.
More details can be found in the Mountain Weather Forecast.
