Snowfall amounts are uncertain, and higher amounts are possible south of Highway 1 (TCH).
If you see more than 25 cm of new snow overnight, consider the avalanche danger to be HIGH.
Several persistent weak layers exist in the upper meter of the snowpack. Large triggers like cornice fall or smaller avalanche's could step down to these layers, initiating very large avalanches.
New and reactive storm slabs are building at upper elevations. With wind transported snow, these slabs are likely deeper on north through east aspects.
Rain at lower elevations on all aspects and brief periods of sun on solar aspects can trigger natural wet loose avalanches.
Reactive storm slabs are likely on Tuesday at upper elevations.
On Sunday, continued natural wet slabs, glide slabs, wet loose and cornice failures up to size 2.5 were reported. Rider-triggered wind slabs were also reactive on north aspects in the alpine up to size 1.
Large natural cornice failures continue to be reported and are a prime suspect for triggering persistent slab avalanches.
By Tuesday morning, 15 to 30 cm of new snow may fall at treeline and above. High north aspects will see the deeper accumulations. Solar aspects and lower elevations on all aspects will present as moist snow, especially when the sun comes out.
Below this, a 5 to 25 cm crust from the late March rain event is present. This is capping a moist upper snowpack.
The primary weak layer of concern was buried in early March, consisting of surface hoar, facets, and a crust is now 80 to 150 cm deep.
Deeper weak layers from February and January are buried 150 to 200 cm deep.
Monday Night
Cloudy with snow 10 to 25 cm. 25 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level falling to 1200 m.
Tuesday
Cloudy with sunny periods and snow 5 to 10 cm. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1800 m.
Wednesday
Cloudy with flurries 2 to 8 cm. 15 to 20 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1700 m.
Thursday
Mix of sun and cloud. 15 to 25 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 2500 m.
More details can be found in the Mountain Weather Forecast.
