Persistent slabs are possible to trigger in areas where the snowpack transitions from thick to thin or by a falling cornice
Evaluate terrain and reduce your time travelling below cornices
Various weak layers from the past 3 months are a concern in shallow north facing terrain. Be especially leary of slopes that match this description and have a cornice above.
On Sunday explosives were used to drop cornices, some of these cornices triggered deep persistent slabs on the slopes below. The resulting avalanches were up to size 3 with crowns as deep as 3 meters.
The upper snowpack is highly variable. A crust exists on or near the surface on all aspects below treeline and on all sun exposed slopes. On north aspects, Up to 10 cm of snow has buried a melt-freeze crust from late March that increases in thickness as you gain elevation. Below these crusts, the upper snowpack is moist.
Several week layers from early March, mid February and late January can be found in the mid and lower snowpack.
The base of the snowpack is generally faceted.
Precipitation amounts over the next 24hrs could be highly variable due to convection.
Monday Night
Mix of cloud and clear skies with 0 to 3 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature -7 °C.
Tuesday
Mostly cloudy with 1 to 5 cm of snow. 10 to 20 km/h west ridgetop wind. Treeline temperature -4 °C.
Wednesday
Mostly cloudy with up to 10 cm of snow. 15 to 30 km/h west ridgetop wind. Treeline temperature -5 °C.
Thursday
Mix of sun and cloud with up to 10 cm of snow. 10 to 20 km/h northeast ridgetop wind. Treeline temperature -7 °C.
More details can be found in the Mountain Weather Forecast.
