Avalanche Forecast

Monday night: Clear, light northwest winds, alpine temperature -18 C.

Tuesday: Increasing cloud, 5-10 cm of snow, light southwest winds gusting strong at ridge-top, alpine high temperature -11 C. 

Wednesday: Cloudy, 10-20 cm of snow, light southwest winds gusting at ridge-top, alpine high temperature -8 C. 

Thursday: Cloudy, isolated flurries, light southwest winds gusting at ridge-top, alpine high temperature -8 C. 

During the storm, numerous large (size 2-3) avalanches released naturally in the storm snow. These avalanches primarily occurred on leeward aspects at treeline and alpine elevations. A very large cornice fall was reported Sunday on a north aspect at 2400 m, and it stepped down to a large slab avalanche. Below tree line, large wet loose avalanches were releasing naturally on Friday and into Saturday.

With continuous stormy weather over the past week, there have been a handful of notable natural avalanches reported in the north of the region. These were very large (size 3-4) persistent slab avalanches breaking 100-250 cm deep on southeast, east, and northwest slopes above 2000 m. Although the likelihood is decreasing in the aftermath of the storm, wind slab avalanches or large cornice fall may have the potential to step-down to this layer.

There have been substantial changes to the snowpack over the past few days. 40-80 cm of snow fell during the weekend storm above 1900 m, with the higher totals in the northeastern parts of the region. Extreme winds originating from the southwest and shifting to the northwest created a tricky loading pattern at treeline and above and increased concern for cornice triggers. These winds drifted the snow into slabs on leeward terrain features that may be possible to human trigger. During a warming event Saturday night, rain saturated snow surfaces up to around 1900 m that have since formed a crust.

The mid and lower snowpack is generally well settled and strong. In the north of the region, a weak layer of surface hoar buried 90 to 170 cm deep may persist in isolated areas.

• Remember that the snowpack will be significantly different at higher elevations than lower down.
• Stay off recently wind loaded slopes until they have had a chance to stabilize.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.