Avalanche Forecast

On Wednesday, a size 2 natural windslab avalanche was reported on E-SE aspects in the alpine.

On Friday, a size 2.5 skier-triggered deep persistent slab occurred in the Birkenhead. This avalanche was remotely triggered, meaning the skier was a distance away from the slab when it occurred (100 m above). It occurred on a wind-loaded slope in the alpine during a period of strong solar radiation. The crown was 150 cm deep.

Looking forward to Sunday, riders should be cautious around pockets of stiff wind slab at upper elevations. These slabs may fail easily where they overlie a slick crust and will be in more atypical locations, as northerly winds have created a reverse-loading pattern. Riders should also be aware of the potential for large and surprising deep persistent slab avalanches. These avalanches are most likely to occur in rocky, shallow, wind-loaded terrain in the alpine or upper treeline.

Please continue to share any observations or photos on the Mountain Information Network.

10-20 cm of recent storm snow sits over wind-affected surfaces at higher elevations and a crust below 1800 m. On steep solar slopes, a sun crust can be found on the surface.

In the midpack, a weak layer can be found 50-100 cm deep, as a decomposing crust, or in many places, it's more of a soft and weak section of the snowpack. There is a widespread weak layer of facets and depth hoar at the bottom of the snowpack.

Generally, the snowpack in this region is weak and shallow. Snowpack depths around treeline are highly variable and range between 150 - 230 cm.

Saturday night

Clear Alpine temperatures reach a low of -18 °C. Ridge wind light to 40 km/h from the north. Freezing level at valley bottom.

Sunday

Sunny. Alpine temperatures reach a high of -8 °C. Mostly light ridge wind occasionally gusting to 35 km/h from the north. Freezing level at valley bottom.

Monday

A mix of sun and cloud. Alpine temperatures reach a high of -6 °C. Mostly light ridge wind occasionally gusting to 30 km/h from the west. Freezing level at valley bottom.

Tuesday

Cloudy with sunny periods and isolated flurries. Alpine temperatures reach a high of -9 °C. Ridge wind light to 25 km/h from the west. Freezing level at valley bottom.

More details can be found in the Mountain Weather Forecast.

• Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
• Wind slabs may be poorly bonded to the underlying crust.
• Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
• Be mindful that deep instabilities are still present and have produced recent large avalanches.