Avalanche Forecast

Issued: Feb 26th, 2017 3:49PM

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

Large persistent slabs are still reactive to light triggers like skiers and snowmobiles. Be very cautious around shallow snowpack areas.

Summary

Confidence

Moderate - Wind speed and direction is uncertain

Weather Forecast

MONDAY: Cloudy with sunny periods, light west winds, alpine temperatures around -17 C.TUESDAY: Cloudy with flurries starting in the afternoon, southwest winds with moderate gusts, alpine temperatures around -15 C.WEDNESDAY: 5-10 cm of new snow, moderate southwest winds, alpine temperatures around -10 C.

Avalanche Summary

Recent avalanche reports in the region are limited to size 1 wind slabs in the alpine and fast moving sluffs. However, many parts of the region have a similar snowpack structure to Clemina Creek, where two size 2 snowmobile triggered persistent slab avalanches were reported on Saturday (see MIN report here). Triggering a large deep persistent slab avalanche is a low probability - high consequence scenario that warrants an extra cautious approach to terrain. See here for a list of recent near misses in the Cariboos and North Rockies.

Snowpack Summary

A recent dusting of new snow came with moderate winds that has likely left thin reactive winds slabs at higher elevations. Light flurries over the past week have delivered a total of 15-30 cm of low density snow, while sun crusts have formed 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. Some lingering surface hoar layers from January are 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 be 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 and produce large destructive avalanches.
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.Avoid lingering in runout zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs
Fresh wind slabs exist 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 27th, 2017 2:00PM