Archived

Avalanche Forecast

Mar 26th, 2014–Mar 27th, 2014

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

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

3: Considerable

The avalanche danger rating at treeline will be considerable

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: Glacier.

New soft slabs are forming in the alpine and tree-line. Keep your eye attuned to changing danger levels with increasing winds and snowfall.

Weather Forecast

Rogers Pass seems to be stuck between the main flow of precipitation to the south and the cold air to the north. As a result, we will likely see light precipitation today, moderate WSW winds, and freezing levels rising to 1300m. This should continue into tomorrow.

Snowpack Summary

We had 20cm overnight. This buried settled snow on E and N aspects, and a sun crust on S and W aspects. Within the upper metre, several crusts are present, including the March 2 crust (down ~1m) which reacts with hard sudden results in tests. There is still large potential for propagation! The Feb10 layer is down ~2m, shallower in thin areas.

Avalanche Summary

Yesterday saw several solar-triggered loose natural avalanches in the highway corridor and in the backcountry to size 3.0. From Friday in Grizzly Bowl, east aspect, ~2600m, a size 3.5 avalanche slid, showing wide propagation from a large trigger (cornice).

Confidence

Track of incoming weather systems is uncertain

Avalanche Problems

Storm Slabs

New snow overnight will have formed soft slabs in alpine and tree-line lee features. In wind-sheltered areas, it will likely be good quality skiing.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid lee and cross-loaded terrain near ridge crests.

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 3

Persistent Slabs

The early March weak layer is still reactive with hard, sudden planar results in tests. Sporadic large avalanche events are still occurring on this layer, so heads-up with the new loading overnight. Stick to supported features today.

Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3

Deep Persistent Slabs

Lingering deep in the snowpack is the Feb 10 surface hoar/facet/crust layer. A large event occurred north of Rogers Pass 2 days ago, reminding us that a large trigger could create a very widely propagating avalanche with devastating results.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely

Expected Size: 3 - 4