Sea To Sky

Rapid loading of new snow along with strong winds and rising temperatures are a recipe for dangerous avalanche conditions on Tuesday. Be prepared to back off in your terrain selection and be mindful of hazards building in overhead terrain.

Monday night: Becoming cloudy with initial flurries bringing up to 5 cm of new snow. Moderate southwest winds increasing into the morning.

Tuesday: Cloudy with flurries bringing 15-25 cm of new snow, easing overnight. Moderate to strong southwest winds. Alpine high temperatures around -7.

Wednesday: A mix of sun and cloud. Light west winds. Alpine high temperatures around -10.

Thursday: A mix of sun and cloud. Light variable winds. Alpine high temperatures around -13.

Reports from Sunday showed two natural cornice failures to size 2 on north aspects in the alpine. On Friday, storm snow was reactive to riders and explosives, with many small to large (size 1 to 2.5) avalanches triggered at 20 to 50 cm in depth

Looking forward, an incoming coastal storm is expected to spill significant precipitation amounts into the Sea to Sky over the day on Tuesday. Storm slabs are likely to become increasingly reactive as new snow accumulates and consolidates through settlement and wind redistribution.

15-25 cm of new snow is expected to accumulate in the region over the day on Tuesday. The new snow will bury variable surfaces that include well developed surface hoar in sheltered areas, sun crusts on southerly slopes, and wind-affected surfaces.

Below the current surface, 25 to 35 cm of snow that fell late last week with strong to extreme south to southwest wind, formed wind slabs in lee terrain features at treeline and alpine elevations.

A weak layer of surface hoar crystals and/or faceted grains may be found around 100 cm deep on northerly aspects at treeline and lower alpine elevations. For some of the region, the layer may have been destroyed by strong wind immediately before burial on February 22nd, but it may still exist in sheltered terrain features in parts of the region. In these areas, larger avalanches composed of new snow may cause isolated step down avalanche activity at this layer on Tuesday.

Weak faceted snow and melt-freeze crusts exist near the base of the snowpack in some of the region, particularly the eastern and northern parts. This layer is considered dormant, as it hasn't produced an avalanche since February 20th. This layer may require a very large load, such as a cornice fall, or rapid weather changes to reactivate.

• Storm slab size and sensitivity to triggering will likely increase through the day.
• Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.