Archived

Avalanche Forecast

Jan 28th, 2017–Jan 29th, 2017

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

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

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: South Coast Inland.

Danger will increase towards the north. Little change is expected for the Coquihalla area, but northern areas are expecting up to 20 cm of new snow falling on a weaker snowpack.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

SUNDAY: Scattered flurries with 5-10 cm in the south and 10-20 cm in the north, strong southwest winds, freezing levels dropping to 1200 m.MONDAY: Cloudy with sunny periods, light west winds with moderate gusts, freezing levels dropping with alpine temperatures around -3 C in the south and -7 C in the north.TUESDAY: Isolated flurries with trace accumulations, light north winds, alpine temperatures around -8 C.

Avalanche Summary

On Friday, two skiers were caught in a size 2 wind slab avalanche that carried them down a steep north facing couloir in the Coquihalla area. Old wind slabs are likely lingering in immediate lee terrain, and new wind slabs will likely form on Sunday. Larger wind slabs are expected in the northern areas around Duffey Lake and the South Chilcotins, where there are greater amounts of snow in the forecast and widespread surface hoar on the surface.

Snowpack Summary

SOUTHERN AREAS (e.g. Coquihalla): Light flurries will bury a variety of crusts and settled storm snow with isolated wind slabs lingering on northerly aspects.NORTHERN AREAS (e.g. Duffey Lake): Moderate flurries will bury a hard surface composed of settled storm snow, crusts, and surface hoar. Strong southwest winds will form fresh wind slabs. The upper snowpack has 50-80 cm of settled storm snow sitting above the mid-January surface hoar and facet interface. This interface produced large avalanches during the last storm cycle, and may still be poorly bonded in thin snowpack areas such as the South Chilcotins.

Avalanche Problems

Wind Slabs

Watch for new wind slabs forming on lee and crossloaded features. In low snow areas to the north, be aware of the potential for wind slab avalanches to 'step down' to deeper weak layers.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Avoid freshly wind loaded features.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2