Avalanche Forecast

Issued: Dec 16th, 2017 5:07PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

mgrist, Avalanche Canada

Sea To Sky.

Wind-driven snow will increase the avalanche danger on Sunday. Watch for how the new snow is bonding to the old surface.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday

Weather Forecast

After a long drought we'll see some new snow, blown in by southwest winds. SUNDAY: Snow. Accumulation 10-15 cm. Ridge wind moderate from the southwest. Freezing level 1000 m.MONDAY: Cloudy, flurries. Accumulation up to 5 cm. Ridge wind light from the west. Freezing level 700 m.TUESDAY: Snow. Accumulation up to 10-20 cm. Ridge wind moderate from the south west. Freezing level 800 m.

Avalanche Summary

No new avalanches reported.Avalanche activity is expected to increase with the wind-driven snow on Sunday, especially on north through east aspects at higher elevations.

Snowpack Summary

A light dusting of new snow covers the melt-freeze crust that formed on all aspects and elevations. On north aspects this crust is thin with dry, sugary snow crystals (facets) below. Beneath the surface, the upper snowpack is well settled and overlies a thin layer of facets on the late-November rain crust. Snowpack tests found hard, sudden compression test results on the facets just above the crust, which is now down approximately 50 cm at tree line elevations. The lower snowpack is well settled and consists of several crusts that formed in the early season.

Problems

Wind Slabs

The new storm snow may be easily triggered, especially in areas with additional loading from wind.

Be careful with wind loaded pockets in down wind areas, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.Watch for signs of instability such as whumpfing, shooting cracks or recent natural avalanches.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 17th, 2017 2:00PM