Avalanche Forecast

Issued: Jan 8th, 2017 3:57PM

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

Avalanche Canada jsmith, Avalanche Canada

Wind is driving the avalanche danger on Monday. I would expect to find touchy wind slabs on lee features below ridgetops and good skiing in sheltered terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

MONDAY: Snow beginning Sunday evening and is expected to accumulate to 10-20 cm by Monday afternoon. Moderate southwesterly ridgetop winds, and temperatures around -12.TUESDAY: Mix of sun and cloud, moderate northwesterly ridgetop winds, and temperatures around -18.WEDNESDAY: Mostly sunny with cloudy periods, light northwesterly ridgetop winds, and temperatures around -20.

Avalanche Summary

On Saturday, numerous size 1 human triggered wind slabs were reported on northerly aspects. I expect human triggered wind slab activity to increase on Monday with the forecast new snow and wind.

Snowpack Summary

Forecast 10-20 cm of new snow by Monday afternoon and moderate southwest winds are expected to create fresh wind slabs on lee features at treeline and above. Recent snow has also covered old, thicker wind and hard slabs from previous wind events. Persistent weak layers in the mid-pack are giving variable results in snowpack tests, but are generally most touchy in shallow snowpack areas. Recent snowpack tests gave moderate to hard but resistant results on two different layers of facets and/or buried surface hoar in the top metre. The lower snowpack seems to be well bonded, but features a crust/facet deep persistent weakness near the ground, which remains a concern in shallow rocky snowpack areas.

Problems

Wind Slabs

An icon showing Wind Slabs
Expect wind effected terrain to be significantly more reactive than sheltered areas. Watch for signs of instability such as whumphing, cracking, and recent avalanches.
Avoid areas where the snow feels stiff or slabby.Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 9th, 2017 2:00PM