Archived

Avalanche Forecast

Mar 11th, 2016–Mar 14th, 2016

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

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

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

1: Low

The avalanche danger rating below treeline will be low

Regions: Waterton Lakes.

Winter returns at upper elevations, time to get back in the mind set of choosing terrain carefully. JH

Weather Forecast

Saturday: A cold front passes over the area giving; moderate to strong SW wind; 10-15 cm of snow, and freezing levels spiking to TL as the front approaches then dropping to valley bottom.Sunday-Monday: Unstable air in the wake of the front will give ongoing cool temps, cloudy skies and flurries. Accumulations of up to 10cm are forecast.

Snowpack Summary

Thursdays heavy snowfall and strong SW winds built storm slabs up to 40cm deep over the early March rain crust (present on all aspects into the lower alpine), these remained sensitive to human triggering Friday. The mid and lower snowpack is generally well consolidated, and is made up of a series of crusts at lower elevations and on solar aspects.

Avalanche Summary

Numerous naturally triggered small to large storm slab avalanches occurred on N-E (lee) aspects during Thursdays storm. Ski cutting in a steep lee at treeline produced a small (size 1.5) storm slab avalanche on Friday, this was observed to have run on the early March crust.

Confidence

Forecast snowfall amounts are uncertain

Avalanche Problems

Storm Slabs

Snow showers through the weekend will continue to add to the load on the early March crust. With this crust as a potential weak interface these storm slabs may be slow to strengthen.

Avoid steep lee and cross-loaded slopesBe careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Expect ongoing cornice development with warm temperatures and snowfall at the start of the weekend. These may become brittle as temperatures cool.

Give cornices a wide berth when traveling on ridges.Minimize exposure to overhead hazard from cornices.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Loose Wet

Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 1