Avalanche Forecast

Issued: Feb 24th, 2017 3:04PM

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

Avalanche Canada shorton, Avalanche Canada

Avoid lingering in runout zones and watch for shallow snowpack areas where triggering a deep persistent slab avalanche remains possible.

Summary

Confidence

High - The weather pattern is stable

Weather Forecast

SATURDAY: Cloudy with light flurries in the afternoon with 2-4 cm of new snow, moderate west winds, alpine temperatures around -12 C.SUNDAY: Mix of sun and cloud, light north winds, alpine temperatures around -16 C.MONDAY: Mix of sun and cloud, light northwest winds, alpine temperatures around -16 C.

Avalanche Summary

Few avalanches have been reported the past few days. On Thursday, ski cutting produced a few size 1 wind slabs on northerly alpine features. Some fast moving sluffing in the recent snow was also reported in steep alpine terrain. Last weekend, several larger avalanches were reported, including a remotely triggered size 3 avalanche on a deep persistent weak layer near Valemount. See here for a list of recent near misses in the Cariboos and North Rockies.Watch for isolated wind slabs at higher elevations and stay aware of the low probability - high consequence scenario of triggering a deep persistent slab avalanche.

Snowpack Summary

Light flurries over the past few days delivered 15-30 cm of low density snow. Expect to find isolated pockets with thicker wind deposits at higher elevations as well as sun crusts forming on steep south slopes. The recent snow has buried the mid-February interface, which is composed of a thick rain crust up to about 1700 m, sun crusts on steep solar aspects, and spotty surface hoar on shaded aspects. The persistent weakness from mid-January is now down about a metre and the weak facets buried in mid-December are down about 1.5 metres. These deep persistent weaknesses still have the potential to wake up and become reactive with human triggers.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
A weak layer of facets near the bottom of the snowpack is lingering and may be triggered in shallow snowpack areas, resulting in large destructive avalanches.
Avoid lingering in runout zones.Carefully evaluate and use caution around thin snowpack areas.Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs
Small wind slabs have been lurking below ridge crests and behind terrain features at higher elevations.
Avoid recently wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 25th, 2017 2:00PM