Avalanche Forecast

Issued: Dec 7th, 2016 3:58PM

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

Avalanche Canada jfloyer, Avalanche Canada

Watch for wind blowing snow around at ridgetop that indicates wind slabs are forming on exposed downwind slopes.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Thursday: Dry, some high cloud and cold. Treeline temperatures around -23 C. Winds easterly 50-70 km/h.Friday: Increasing cloud, but staying dry. Treeline temperatures around -22 C. Winds easterly 60 km/h, diminishing during the day.Saturday: Flurries. Temperatures around -25 C. Light or moderate easterly winds.

Avalanche Summary

Wind slabs avalanches are a concern where wind is being blown around. No new avalanche reports on Tuesday or Wednesday; however; check out the new MIN report for the Miller Ck/ Crater Lk area. That report indicated a natural size 2 slab avalanche which appeared to be a cornice failure in steep complex terrain. The avalanche was noted from a southeast aspect at 1850 m. The crown was 20-30 cm thick, 60 m wide and running up to 300 m in length.

Snowpack Summary

Recent winds have blown from many directions, most recently from the east. As a result, expect wind slabs to exist on a wide variety of exposed slopes. A layer of surface hoar was reported around Hudson Bay Mountain last week, which now sits beneath 40-50 cm of settling snow. A thick rain crust that formed in early November is now buried 50-60 cm deep, and recent snowpack tests produced sudden results on facets (sugary snow) above this crust. Early season snowpack observations are still very limited in the region, but reports suggest the average snowpack depth is 50-90 cm at treeline and 120 cm or greater in the alpine.

Problems

Wind Slabs

An icon showing Wind Slabs
New wind slabs may exist in the alpine and on exposed features at treeline. Wind slabs may be touchy in areas with buried surface hoar.
Tread cautiously on open slopes and convex rolls where buried surface hoar may be preserved.Watch your transition into wind affected terrain. Some areas may have been reverse loaded by winds.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 8th, 2016 2:00PM