Archived

Avalanche Forecast

Dec 7th, 2016–Dec 8th, 2016

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

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

Regions: Kootenay Boundary.

Caution as you transition into wind affected terrain, as lingering wind slabs exist.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

THURSDAY: Mix of sun and cloud, light south winds, alpine temperatures at -15.FRIDAY: Flurries with accumulations of 5-10 cm, 20-40 southwest winds, alpine temperatures at -15.SATURDAY: Isolated flurries, light west winds, alpine temperatures at -12.

Avalanche Summary

Small loose dry avalanches have been reported in steep terrain the past few days. Cornice control on Tuesday triggered a size 3 wind slab on a very steep cross-loaded northeast slope at treeline (See the YAMMY report on the MIN). This report is a good reminder that although there have been few reports of wind slab avalanches recently, it is critical to identify wind loaded terrain features

Snowpack Summary

25 cm of low density snow from last weekend sits above a thin drizzle crust in many places and is gradually settling. Northerly winds have redistributed the snow, forming stubborn wind slabs in exposed areas. New surface hoar up to 10 mm in size has been reported growing on the surface, and will continue to develop during this fair weather period. Watch for slopes that develop surface hoar or surface facets, because new snow will bond poorly when the next storm arrives. A thick melt-freeze crust from mid-November is buried 40-80 cm deep. Facets have recently been reported above this crust and may continue to develop with the cold temperatures. Facet growth will be most pronounce in shallow alpine start zones, creating the potential for large avalanches in the future. Snowpack depths are 130-160 cm at treeline elevations.

Avalanche Problems

Wind Slabs

Lingering wind slabs from the weekend may still be reactive to human triggering in leeward and cross-loaded features. Wind slabs are possible on any aspect with winds recently shifting to the north.

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: Possible

Expected Size: 2 - 2