Archived

Avalanche Forecast

Jan 27th, 2019–Jan 28th, 2019

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: Northwest Inland.

Wind slabs are likely to be encountered at upper elevations and may be reactive to human triggering, especially in lee features.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SUNDAY NIGHT - Cloudy with clear periods / light northeast winds / alpine low temperature near -4 MONDAY - A mix of sun and cloud / light variable winds / alpine high temperature near -5 TUESDAY - Cloudy with scattered flurries / southwest winds, 10-20 km/h / alpine high temperature near -5 WEDNESDAY - Flurries, 2-4 cm / southwest winds, 20-40 km/h / alpine high temperature near -3

Avalanche Summary

No new avalanches have been reported in the region.A natural avalanche cycle likely occurred in the region during Friday's storm.A large (size 2.5) storm slab avalanche was triggered remotely (from 20 m away) by a skier in the Howson Range on Tuesday. This occurred on a southwest aspect at 1700 m and the slab had a depth of about 30 cm.

Snowpack Summary

Recent new snow and wind has formed wind slabs at upper elevations.In the alpine and at upper treeline elevations, this recent snow likely sits on a weak layer of surface hoar (feathery crystals) in wind sheltered areas. At lower elevations, the recent precipitation fell as rain. The surface has formed a melt-freeze crust below treeline and possibly into treeline as well.The bottom 30 to 50 cm of the snowpack consists of a weak combination of facets (sugary snow) and crusts, particularly in areas where the snowpack is shallow. It may be possible for large triggers such as cornice failures or rock fall to trigger avalanches on this layer.

Avalanche Problems

Wind Slabs

Up to 30 cm of snow has been redistributed by recent strong winds. This snow may be sitting on a weak layer of surface hoar (feathery crystals).

Be careful with wind loaded pockets near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2