Avalanche Forecast

Issued: Feb 1st, 2017 4:14PM

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

swerner, Avalanche Canada

Sea To Sky.

Lingering wind slabs continue to be reactive to rider triggers.

Summary

Confidence

High - The weather pattern is stable on Thursday

Weather Forecast

Thursday: A mix of sun and cloud with alpine temperatures near -10. Ridgetop winds light from the East.Friday: Snow amounts 5-10 cm with alpine temperatures near -5 and freezing levels 1200m. Ridgetop winds light from southeast.Saturday: Snow amounts 5-15 cm with alpine temperatures near -2. Freezing levels 1300 m and ridgetop winds light-gusting strong from the southwest.

Avalanche Summary

On Tuesday, a size 1 wind slab was reported from the Brandywine area. Isolated wind slabs may continue to be reactive in the lee of exposed terrain.

Snowpack Summary

Up to 15 cm of snow fell last weekend. That combined with strong winds have formed stiff, yet reactive wind slabs in the lee of exposed terrain. The new snow sits above a thin breakable sun crust and isolated pockets of buried surface hoar, which provides a weak sliding interface below the new snow. Some recent snowpack tests have shown hard, yet sudden planar results on the mid-January interface (facets) buried approximately 60-100 cm down. A total of 60-120 cm of settled storm snow now forms the upper snowpack and is generally bonded to a crust below. The exception may be thin rocky areas. The mid and lower snowpack are generally well settled, but still feature a number of facet and crust layers that are currently dormant but require monitoring with significant change

Problems

Wind Slabs

With recent switching winds, all aspects may have pockets of wind slab on exposed higher elevation features near ridge crests and cross-loaded slopes.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Use ridges or ribs to avoid pockets of wind loaded snow.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2017 2:00PM