Archived

Avalanche Forecast

Jan 30th, 2017–Jan 31st, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Kootenay Boundary.

Watch for changing conditions at higher elevations and be cautious around thin rocky areas where wind slabs could step down to deeper weak layers. Thanks to everyone who's shared observations on the MIN!

Confidence

Moderate - The weather pattern is stable

Weather Forecast

TUESDAY: Sunny with cloudy periods, light east winds, alpine temperatures around -10 C.WEDNESDAY: Sunny with cloudy periods, light east winds, alpine temperatures around -12 C.THURSDAY: Sunny, light east winds, alpine temperatures around -12 C.

Avalanche Summary

On Monday, several size 1 wind slab avalanches were skier triggered in the lee of ridgetops. Isolated natural wind slab activity in the size 1.5-2 from a few days ago was also reported. A large natural avalanche (size 2.5) was reported on a wind-loaded east facing slope in the Rossland range. This avalanche likely released on a deeper persistent weak layer.Expect wind slabs to linger on lee and crossloaded features at higher elevations.

Snowpack Summary

A variety of surface conditions exist including wind affected snow, sun crusts, shallowly buried surface hoar, and pockets of light snow. A total of 30-50 cm of settled snow now sits above a weak interface that was buried in mid-January. The interface is composed of weak facets, surface hoar, and/or sun crusts. The strength of this interface is variable, but has continued to give some sudden results and propagations in snowpack tests. Areas with thin snowpacks (e.g. less than 150 cm) have a generally weak snowpack structure with sugary facets near the ground. This includes shallow alpine slopes and most of the Rossland range. These deeper weaknesses warrant long term monitoring, as they could reawaken with a sudden change in the weather.

Avalanche Problems

Wind Slabs

Watch for pockets of wind slabs on exposed features near ridge crests and cross-loaded gullies. Also be cautious around thin rocky areas where wind slabs could 'step down' to deeper weak layers.

Avoid steep convexities or areas with a thin or variable snowpack.Use ridges or ribs to avoid pockets of wind loaded snow.Avoid convexities or areas with a thin or variable snowpack.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2