Archived

Avalanche Forecast

Dec 29th, 2016–Dec 30th, 2016

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

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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: Lizard-Flathead.

If you are riding Corbin or other shallow snowpack areas, the South Rockies forecast region may be more applicable to your local conditions at this time.

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

FRIDAY: Dry with some sunny spells. Winds mostly light soughwesterly. Treeline temperatures around -6C. SATURDAY: Dry with some sunny spells. Ridgetop winds 20-40km/h from the southwest. Temperatures around -8C.SUNDAY: Light snow in the morning, 5-10 cm. Winds becoming moderate northeasterly. Temperatures around -13C.

Avalanche Summary

On Thursday small size 1 avalanches could be easily ski cut behind ridgecrests on all aspects in the new snow. A large human-triggered avalanche was reported near Corbin in the Flathead Range in an area where wind had firmed up the surface snow but where sugary facets were present lower down in the snowpack.

Snowpack Summary

Quite a lot (up to 50 cm) of recent low density snow has fallen, which is now available to be redistributed by mostly moderate southwesterly winds. The new snow sits above a variety of surfaces including old hard wind slabs and surface hoar. The cold weather in early December left several layers of weak surface hoar and facets which are now buried 50-80 cm deep. These layers have been inactive for the past week, as it appears the lower snowpack is well-settled. A thick crust rain crust from mid-November is near the bottom of the snowpack and remains well bonded to the surrounding snow.

Avalanche Problems

Wind Slabs

Expect fresh wind slabs to form at higher elevations as winds pick up and redistribute loose snow. In shallow snowpack areas, these slabs could pull out to deeper layers below, increasing the severity of an avalanche.

Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.In shallow areas, be aware of the potential for avalanches to step down to deeper snowpack layers.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2