Avalanche Forecast

Issued: Dec 30th, 2017 4:42PM

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

Avalanche Canada ghelgeson, Avalanche Canada

Wind loaded slopes near ridge crest may still harbor a human trigger-able storm slab, especially where the snow has been formed into a stiffer slab by the wind.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

After a succession of snowstorms over southern BC, the weather over the lower mainland will settle into a dry period as 2017 comes to an end and 2018 begins. All indications point to the dry spell lasting until at least mid-week.SUNDAY: Clear skies, freezing level beginning at sea level rising to 2500 m in the late afternoon, light northwest wind, no snow expected.MONDAY: Scattered cloud, freezing level around 2500 m, light variable wind, no snow expected.TUESDAY: Scattered cloud, freezing level around 3000 m, light variable wind, no snow expected.

Avalanche Summary

No new avalanche activity was reported on Friday. On Thursday skiers intentionally triggered avalanches on northwest trough southeast facing slopes to size 1.5. Crowns averaged 20 to 30 cm in depth and up to 90 m in width. Ski tourers noted shooting cracks on unsupported slopes while touring near the Lions. They also reported natural avalanches from the steep slopes below the Lions.

Snowpack Summary

Two successive storms produced 40 to 80 cm of snow over the last few days. Friday night's storm started as rain before turning to snow overnight. The brief period of rain followed by snow and cooling temperatures is thought to have helped the snowpack to settle and stabilize.50 to 100 cm below the surface you'll likely find a couple of melt-freeze crusts which were buried mid-December. This interface has been dormant and has not produced any recent avalanche activity. Below this, the snowpack is thought to be strong and well settled. The snowpack depth is about 160 cm at 1000 m, 220 cm at 1250 m. Many early season hazards are still present at lower elevations.

Problems

Storm Slabs

An icon showing Storm Slabs
The brief period of rain Friday night and cold temperatures should allow the snowpack to quickly settle and stabilize, but there may be the odd human trigger-able storm slab in wind loaded terrain near ridge crest.
Caution in lee and cross-loaded terrain near ridge crest.Use ridges or ribs to avoid pockets of wind loaded snow.Be careful with wind loaded pockets, especially near ridge crest and roll-overs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 31st, 2017 2:00PM