Sea To Sky

Watch out for new wind slabs as well as thick, old wind slabs. They have been reactive to natural and human activity. Don't be complacent with the weak layer lurking in our snowpack, as it has produced large avalanches recently.

Moderate -

TUESDAY: Cloudy with light snowfall, accumulation 2 to 5 cm, light to moderate west winds, alpine temperature -7 C, freezing level 1200 m.WEDNESDAY: A mix of sun and cloud, light southeast winds, alpine temperature -6 C, freezing level 1300 m.THURSDAY: Morning sun and afternoon clouds, light southwest winds, alpine temperature -5 C, freezing level 1400 m.

On Sunday, a large (size 3) persistent slab avalanche was remotely triggered on a north aspect in alpine terrain after substantial air temperature and solar warming over the day. The avalanche likely released on the weak layer described in the Snowpack Summary.Otherwise, loose wet avalanches were easy to initiate in the afternoon with solar warming. Evidence of large slab avalanches was observed, likely occurring early in the weekend.

10 cm of new snow has been redistributed into lee terrain features from strong north to northeast winds. This overlies variable surfaces, including wind slabs at high elevations, a sun crust on south aspects, and a temperature crust on all aspects up to 1900 m. Previous wind slabs are up to 1 m deep from strong south winds. Ridgelines are heavily corniced and if they fail they could trigger slabs on slopes below.A weak layer consisting of surface hoar, facets, and/or a melt-freeze crust from late March is now buried about 60 to 140 cm. This layer is spotty in its distribution and has recently produced large and destructive avalanches. It is mostly likely to be problematic on west, north, and east aspects between 1900 m and 2250 m. Professionals are treating it seriously and avoiding terrain because of it.Below this, the snowpack is well-settled and strong.