Stormy conditions have the potential of triggering an avalanche cycle.
Stormy conditions on Sunday night into Monday will rapidly form new storm and wind slabs. The slabs are likely to form quickly, with the deepest deposits found in lee terrain features from strong southwest wind. A natural avalanche cycle may occur during periods of rapid loading.
Rain will fall below around 800 m, soaking an already wet snowpack. Small wet loose activity may occur in steep terrain features.
SUNDAY NIGHT: Cloudy with snowfall, accumulation 15 to 25 cm, 60 km/h southwest wind, alpine temperature -3 C, freezing level 700 m.
MONDAY: Cloudy with snowfall, accumulation 10 to 20 cm, 40 km/h west wind, alpine temperature -5 C, freezing level 800 m.
TUESDAY: Cloudy with snow and rain, accumulation 20 to 30 cm above 1200 m and rain below, 60 km/h southwest wind, alpine temperature -3 C, freezing level 1200 m.
WEDNESDAY: Cloudy with rain, accumulation 20 to 40 mm, 70 km/h southwest wind, alpine temperature 1 C, freezing level 2000 m.
There's many reports of a widespread natural avalanche cycle that occurred during stormy weather on Thursday to Friday. On Saturday, more storm and wind slab avalanches were triggered by explosives, generally being large (size 2 to 2.5) and about 50 cm deep within recent snow. At low elevations, wet loose avalanches were observed.
Looking forward, a natural avalanche cycle may occur overnight Sunday into Monday during periods of rapid loading from snow and wind.
Above 800 m, anywhere from 20 to 40 cm of snow is expected to accumulated by Monday afternoon with strong southwest wind. This snow will form new storm slabs in areas sheltered from the wind and new wind slabs in exposed terrain. Below 800 m, the precipitation will fall as rain, soaking an already wet snowpack.
The snow will sit on previous storm snow that has totaled around 40 to 60 cm since early February above around 1000 m. This snow may sit on a weak layer of surface hoar crystals, particularly around treeline elevations in terrain features sheltered from the wind. This layer may be found immediately above a hard melt-freeze crust.
Deeper in the snowpack, another surface hoar layer from mid-January may be found around 80 to 120 cm deep at higher elevations in sheltered terrain. This layer is becoming harder to trigger but is most problematic where it overlies a hard melt-freeze crust.
