Storm slabs at upper elevations may be reactive to rider triggering.
Even brief periods of sunshine will affect the new snow and trigger wet loose avalanches on steep slopes facing the sun.
New and reactive storm slabs are building at upper elevations. With wind transported snow, these slabs are likely deeper on north through east aspects.
Wet loose avalanches are possible during daytime warming on steep slopes facing the sun or below treeline where the snowpack is wet.
On Monday, natural wet loose avalanches up to size 2 were reported. Rider-triggered wind slabs were also reactive on north aspects in the alpine up to size 1.
Large natural cornice failures may occur if its sunny during the heat of the day. These act as a large trigger on slopes below and could trigger deeper persistent weak layers initiating very large avalanches.
15 to 30 cm of new snow exists at treeline and above. High north-facing slopes will see deeper accumulations due to wind transport. A surface crust has formed at treeline and below, but will likely soften with daytime warming at lower elevations and up into the alpine on slopes facing the sun.
Below this, a 5 to 25 cm crust from the late March rain event is present. The new snow may have a poor bond to the underlying crust. This buried crust 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.
Tuesday Night
Cloudy with snow 10 to 20 cm. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level falling to 1400 m.
Wednesday
Mix of sun and cloud with isolated flurries. 20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1800 m.
Thursday
Cloudy with flurries 5 to 15 cm. 25 to 45 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 2200 m.
Friday
Mix of sun and cloud with isolated flurries. 15 gusting to 45 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 2200 m.
More details can be found in the Mountain Weather Forecast.
