Archived

Avalanche Forecast

Jan 15th, 2019–Jan 16th, 2019

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Coast Inland.

Be aware of places with a thin, shallow snowpack or areas which hold pockets of cold, dry snow. These are most suspect for lingering problems. Avalanche hazard is Moderate at treeline elevations north of Pemberton in the South Coast Inland region.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

TUESDAY NIGHT: Cloudy with clear periods. Freezing level valley bottom. Alpine high -1. Light southeast winds. WEDNESDAY: Mostly cloudy. Freezing level 1000 m. Alpine high near -4. Light east-southeast winds. THURSDAY: Cloudy with flurries, up to 5 cm. Freezing level 1200 m. Alpine high near -3. Light to moderate east-north east winds.FRIDAY: Flurries, 5-15 cm with heavier snowfall amounts near the Coquihalla and continuing into Saturday. Freezing level rising from 1200 m. Alpine high near -2. Light increasing moderate southwest winds.More details can be found in the Mountain Weather Forecast.

Avalanche Summary

On Monday, explosives triggered cornices in the alpine and one size 2 loose-wet avalanche on a south aspect at 2200 m. Size 1-2 natural loose wet avalanches were reported on Saturday and Sunday.Small cornice falls were observed near the Coquihalla on Saturday, and on Sunday cornices were triggered by explosives near Duffey Lake. In the neighboring Sea to Sky region, several large cornice falls have occurred during the warm spell - beware if you are in cornice country.One very large (size 3) natural storm slab avalanche was observed on Chipmunk Mountain near Pemberton. This avalanche occurred either Friday or Saturday on a north aspect between 1600-1950 m in un-skiable terrain.

Snowpack Summary

Colder overnight temperatures are promoting better recovery of the snowpack, refrozen crusts may be found on all aspects below about 1800-2000 m; and on sunny aspects in the alpine. These may break down with sunshine and warming through the day. Cold, dry and wind-affected snow may still be found on more north-facing and polar aspects in the alpine and around treeline. Warmth has promoted settlement of the snowpack and helped bond old wind slabs. At alpine elevations, variable areas of wind slabs and dry snow may be found. However, a generally well-settled upper snowpack is reported, with supportive crusts in the upper snowpack that are isolating deeper snowpack weaknesses. Most of our observations come from the Duffey Lake and Coquihalla regions, so if you are venturing further afield, the local snowpack may not be as strong. Please investigate.There remains a small chance of triggering a deeply buried crust/facet layer with a heavy trigger such as a cornice fall, or from a thin spot.

Avalanche Problems

Wind Slabs

Shaded aspects still hold cold, dry snow. Be cautious around cornices and look for wind slabs in lee terrain features.

Be alert to conditions that change with elevation.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2