Avalanche Forecast

High -

Thursday night: no new snow expected. Light to moderate northwest winds and a low of -6 at 1600m.

Friday: sunny with freezing levels around 1500m. Light northwest winds.

Saturday: sunny with light northwest winds. Freezing levels rising to 1500m.

Sunday: Sunny with light northwest winds. Freezing level rising to 1600m.

On Wednesday a size two natural wind slab avalanche was observed in steep alpine terrain on a east aspect.

On Monday explosives triggered numerous cornices, with some subsequently triggering slabs on the slope below. Explosives also triggered a size 3 on the early December crust, this was a reloaded bed surface at 1900m that had previously avalanched.

On Sunday, a ski cut triggered a size 1.5 wind slab at 1950 m on a north aspect which was 15-25 cm thick and a skier accidently triggered a size 2 wind slab which failed down 30-60 cm on the mid-January crust. An explosive-triggered size 2.5 wind slab was also reported which failed on the mid-January crust down 30 cm and then stepped down to an older layer 100 cm deep in the snowpack. 

This MIN report summarizes the recent conditions well and describes natural and human-triggered slab avalanches size 1-2 as well as whumphing and shooting cracks.

A new melt-freeze crust is expected on solar aspects into the alpine and on all aspects below treeline. This crust will likely break down and become moist as the freezing level rises and the sun comes out. Previous strong wind from the southwest through northwest have formed wind slabs at higher elevations and over hanging cornices on some ridge features.

The January 30 interface is now typically down 15-40 cm and consists of a melt-freeze crust at lower elevations and on solar aspects extending into the alpine and surface hoar in sheltered areas at and below treeline. 

The widespread January 18 rain crust is now around 40-100cm deep with weak faceted snow above. It is most prominent in the Lizard range. In heavily wind scoured areas at and above treeline this crust can be found on the surface. 

The early December crust/facet persistent weak layer is now 100-200 cm deep. This layer produced numerous large avalanches in January but is now considered dormant. See this forecaster blog on how to manage this layer as it may come into play again later this season. 

• Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Cornices become weak with daytime heating or solar exposure.
• Be careful as you transition into wind affected terrain.