Avalanche Forecast

Tuesday night: Localized flurries in the southeast corner bringing 5-10 cm. Light northerly wind. Treeline low around -14 °C. Freezing level valley bottom.

Wednesday: Mostly sunny. Light northwest wind. Treeline high around -7 °C. Freezing level valley bottom.

Thursday: Sunny. Light to moderate northwest wind. Treeline high around -5 °C. Freezing level 700 m.

Friday: Sunny. Light to moderate west wind. Treeline high around -3°C. Freezing level 1300 m.

No new avalanche activity reported on Monday. The current cooling trend has helped calm down avalanche activity on buried weak layers, old and new. But the many reports of avalanches over the warm sunny period on the weekend indicate that our various weak layers are still triggerable under the right conditions.

On Sunday a size 1.5 skier triggered persistent slab avalanche was reported in an treeline elevation start zone north of Nelson. Good visibility allowed observation of a 2 day old widespread avalanche cycle in the Valhallas size 2-3.5. One notable stepped down to a weak layer 100 cm deep.

Storm slabs sitting on a weak layer were touchy Friday and Saturday, with several riders getting surprised in the northeast of the region. These avalanches were:

• Large, ranging from size 2-3
• Triggered by skiers, snowmobiles and snow cat. At least one was remote.
• At treeline elevations, on leeward SE-NE aspects.
• Photos and detailed description of the remote in this MIN
• Photos and details of similar incidents in the neighboring South Columbia region here.

South of Nelson, around 10 cm of lightly wind-affected snow sits over a near-surface crust up to 8 cm thick which may make for challenging travel conditions as high as 2250 m. Further north where the crust does not exist, more surface snow is available for wind transport so we anticipate more substantial wind slab development at upper elevations.

A recently buried weak layer sits 20-50 cm deep. It consists of surface hoar crystals in shady, wind-sheltered areas around treeline and a crust on solar aspects. This layer was reactive to human triggers over the weekend in areas where it was not bridged by the above-mentioned crust.

Weak layers from mid-February and late January made up of crusts and/or surface hoar crystals can be found around 60+ cm and 100+ cm deep, respectively. Some recent persistent slab avalanches on this layer have surprised riders, so keep this type of avalanche in mind when making terrain choices.

• A crust on the surface will help bind the snow together, but may make for tough travel conditions.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Avoid steep convexities or areas with a thin, rocky, or variable snowpack.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.