Archived

Avalanche Forecast

Jan 23rd, 2019–Jan 26th, 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

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: Waterton Lakes.

New windslabs may propagate further than expected on buried suncrust and surface hoar layers.

Weather Forecast

Thursday: Mainly cloudy with isolated flurries. Moderate west winds. Alpine high -7Friday: Cloudy with sunny periods and isolated flurries. Moderate west winds. Alpine high -7Saturday: Mainly cloudy with isolated flurries. Moderate southwest winds. Freezing level is uncertain with models predicting anywhere between 1500 and 2200m

Snowpack Summary

30cm of recently wind affected snow has gradually loaded either a suncrust below 2000m on solar aspects or spotty surface hoar in sheltered areas between 1600 and 1900m. This may be a problem layer when we see more snow. The midpack is strong in deep snowpack areas, but the facets lingering at the bottom remain a concern in thinner areas.

Avalanche Summary

Skier controlled wind slabs to 1 were reported in the Castle region yesterday.

Confidence

Freezing levels are uncertain on Saturday

Avalanche Problems

Wind Slabs

Southwest through northwest winds have formed thin wind slabs over a crust / surface hoar layer and may propagate farther than expected. Dig down and investigate the bond of new snow before committing to your line.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Deep Persistent Slabs

This layer likely requires a large trigger. Be cautious when transitioning from thick to thin snowpack areas

Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3