Cornices
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
Cornices are large and looming. Strong winds and warming temperatures may increase the sensitivity. Cornices may trigger wind slabs or may step down to the persistent slab.
5:30 Update Avalanche Hazard is High.
Avoid all avalanche terrain
Heavy rain and high freezing levels are creating very dangerous conditions.
Cornices are large and looming. Strong winds and warming temperatures may increase the sensitivity. Cornices may trigger wind slabs or may step down to the persistent slab.
A crust layer down 60 to 80 cm has been the sliding surface for several recent avalanches. A second deeper weak layer down over 100 cm is a concern at upper elevations, where the crust is thinner or not present.
Rising freezing levels and rain will soften surface snow. Large avalanches are almost certain in steep terrain. Wet slabs are more likely at upper elevations while wet loose will be more likely at lower elevations.
On Tuesday, several natural, cornice and explosive triggered avalanches were reported. Avalanches were a mix of cornice, persistent slab and storm slab and up to size 2.
On Monday, several small rider-triggered wind slab avalanches were reported.
On Sunday, a size 3 avalanche was reported in the Lizard Range below a steep headwall with a 2 meter crown. The avalanche was naturally triggered by a cornice.
High freezing levels and heavy rain are saturating surface snow to ridgetop.
Below this a 1 to 10 cm thick crust can be found on all aspects and is down 50 cm. The thickness of the crust depends on elevation. Several recent avalanches have released to this layer.
At upper elevations, where the crust is thinner or not present, it may still be possible to trigger persistent slabs on multiple buried weak layers of surface hoar and/or crusts in the top 120 cm of the snowpack.
Cornices are large and looming. Avoid traveling underneath them.
The mid/lower snowpack is well settled and strong in most areas.
Tuesday Night
Cloudy. up to 10 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 2300 m.
Wednesday
Cloudy. Up to 10 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 2300 m.
Thursday
Cloudy. 10 to 25 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 2 °C. Freezing level 2400 m.
Friday
Cloudy. 25 to 45 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 4 °C. Freezing level 2700 m.
More details can be found in the Mountain Weather Forecast.