Stormy weather continues !
Avoid avalanche terrain during periods of heavy loading from new snow and wind.
Uncertainty is around how buried persistent weak layers will react to the new load.
A weak layer from early March is now 120 to 175 cm deep with January and February layers buried 150 to 250 cm. There's still uncertainty about how the weak layers will react to the new load.
New snow and wind will create fresh and reactive slabs, especially on lee terrain features. Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Natural storm slabs were observed on northwest alpine slopes, suspected to have run overnight on Wednesday. Several dry loose were reported from steep terrain at treeline around Whistler.
Avalanche activity will increase during this stormy period and a natural cycle is expected.
Thanks for sharing your observations via the MIN if you are going out into the backcountry.
Another 15 to 30 cm of new snow is expected by Friday afternoon, forming touchy storm slabs. This overlies wind-affected snow in lee terrain at upper elevations and moist, heavy snow or a melt-freeze crust on southerly slopes, especially at lower elevations. This sits over 120 to 175 cm of settling storm snow from the past week.
Under it, a weak layer formed in early March that consists of a crust on all aspects except high north-facing slopes and facets or surface hoar in some areas. Weak layers formed in mid-February and late January are now buried 150 to 250 cm deep.
Below this, the snowpack is well-settled and strong.
Thursday Night
Cloudy with 15 to 30 cm of new snow. 50 to 70 km/h south ridgetop wind. Treeline temperature -4 °C. Freezing level 1000 m.
Friday
Cloudy with 10 to 15 cm of new snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1000 m.
Saturday
Cloudy with isolated flurries. 20 to 30 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level 1200 m.
Sunday
Cloudy with 20 to 30 cm of new snow. 50 to 70 km/h south ridgetop wind. Treeline temperature +2 °C. Freezing level 1600 m.
More details can be found in the Mountain Weather Forecast.
