Sea To Sky

The weather has been active and storm slabs have been reactive. Maintain a cautious approach while the storm snow stabilizes.

High -

Sunday night: Flurries bringing approximately 5 cm of new snow. Light southwest winds.Monday: Cloudy with flurries bringing approximately 5 cm of new snow. Light south winds. Freezing level to 1400 metres with alpine temperatures of -4.Tuesday: Periods of snow bringing 15-20 cm of new snow. Moderate to strong south winds. Freezing level to 1400 metres with alpine temperatures of -3.Wednesday: Periods of snow bringing approximately 20 cm of new snow. Light southeast winds. Freezing level to 1500 metres with alpine temperatures around -3.

Reports from Friday and Saturday included numerous observations of storm slabs releasing typically to Size 1.5 with ski cutting and explosives control in the Whistler area. One natural Size 2 wind slab was reported on Friday as well as one remotely triggered Size 1.5 cornice. Crown fractures were typically 20-40 cm deep.Reports from Thursday showed explosives control in the Whistler area producing storm slab releases to Size 2. Crown fractures were generally 50-100 cm thick.Looking forward, storm slabs may reactive to human triggering on Monday, especially in more wind affected and/or unsupported terrain. Concern also exists for large triggers like cornices or storm slabs to step down to the mid-March interface or, in more isolated areas of the alpine, the deeper mid-February weak layers.

Stormy weather over the end of last week brought roughly 50 cm of wind affected new snow to the region. At about 2000 metres and below, this new snow lies above a crust (March 22) that formed over last week's storm snow. Beneath this older storm snow, an older rain crust that was buried around March 15 is now about 80-100 cm deep. The mid-February crust/facet layer can still be found at the upper end of treeline and into the alpine. This interface is now generally 125-165 cm deep but may present at the surface or up to 250 cm deep in heavily wind affected terrain. Although there is growing confidence in this layer becoming dormant, continued caution is warranted while our recently formed storm slabs remain triggerable. A big enough storm slab or cornice release in the right location may have the potential to coax this layer or the shallower March 15 crust layer into reacting.