Avalanche Forecast

Issued: Jan 31st, 2019 3:46PM

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

Avalanche Canada mconlan, Avalanche Canada

New wind slabs will likely form with the incoming storm. Also continue to use caution due to a buried weak layer in the snowpack.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

THURSDAY NIGHT: Mostly cloudy, freezing level below valley bottom.FRIDAY: Cloudy with snowfall, accumulation 5 cm, moderate to strong southwest winds, alpine temperature -2 C, freezing level 1400 m.SATURDAY: Cloudy with morning snowfall and afternoon clearing, accumulation 5 to 15 cm, moderate southwest winds, alpine temperature -4 C, freezing level below valley bottom.SUNDAY: Cloudy with light snowfall, accumulation 5 to 10 cm, light northeast winds, alpine temperature -24 C, freezing level below valley bottom.

Avalanche Summary

A small wind slab avalanche was triggered by a skier on Thursday on an easterly aspect. The likelihood may increase with incoming snow with strong southwest winds.

Snowpack Summary

Snowfall should begin on Friday, which will fall with strong southwest winds. Once enough snow falls, expect to find new wind slabs form in lee and cross-loaded terrain features near ridges. The new snow will overly feathery surface hoar crystals, previously wind-affected snow, and a melt-freeze crust on southerly aspects.Buried around 10 to 40 cm, a weak layer of surface hoar may be found on shady and sheltered slopes. Use added caution between 1500 m and 1900 m, where this layer is most prominent. On southerly aspects, the snow overlies a hard melt-freeze crust all the way to the mountain tops.The remainder of the snowpack is generally well-settled. Thin snowpack areas, such as in the east of the region, may find weak and sugary faceted grains near the base of the snowpack.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Around 10 to 40 cm of snow sits above a weak layer of surface hoar and a melt-freeze crust. The surface hoar is likely best preserved in shaded and sheltered areas between 1500 m and 1900 m. The crust exists on southerly aspects at all elevations.
Watch for signs of instability such as whumpfing, cracking, or recent avalanches.Make observations and assess conditions continually as you travel.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs
New snow is expected to start falling on Friday, which will fall with strong southwest winds. In exposed terrain, this snow will likely be blown into lee and cross-loaded terrain depressions, particularly near ridges.
Use caution in freshly wind-loaded features, especially near ridge crests and in steep terrain.Conditions may deteriorate throughout the day.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Feb 1st, 2019 2:00PM