Avalanche Forecast

Moderate - Timing or intensity of solar radiation is uncertain on Monday

On Monday expect overcast skies in the morning with gradual clearing in the afternoon. Tuesday should be mainly clear with increased cloud forecast for Wednesday.. Ridgetop winds should remain mainly light from the southwest. Freezing levels will climb to about 3500m for Monday and Tuesday, and then drop to about 2200m by Wednesday.

On Saturday, evidence of natural storm slab avalanche activity to size 3 was observed. The avalanches occurred in response to new snow and wind on Friday. Last week, a skier remotely triggered a size 3.0 slab avalanche from 20 metres away that released on the early January surface hoar. This avalanche happened at 2300 metres on a south-southeast aspect in the Duffey Lake area. The fracture propagated 350 metres and ran 750 metres to the valley bottom. This speaks to the ongoing touchy persistent slab problem in the north of the region. Looking ahead, forecast rising freezing levels and solar radiation should spark a round of loose wet avalanche activity on sun-exposed slopes. Warming will also increase the likelihood of triggering cornices, wet slabs and deep and destructive persistent slabs, especially in the north of the region.

On Friday between 25-40cm of new snow fell. Strong southwest winds shifted these accumulations into deep and dense storm slabs. Cornices were already large before the storm, and new growth is expected to be fragile. About 50-80cm below the surface, you'll likely find a rain crust which formed on January 28th. This crust is widespread and exists up to about 1900m. Previous wet and heavy storms have likely flushed out the deeper mid-January surface hoar in the south of the region; however, this weakness which lies between 60 and 130cm below the surface is still reactive at higher elevations in the Duffey, Hurley and Birkenhead areas. This layer continues to produce sudden results in snowpack tests and has been responsible for recent destructive avalanches.