Archived

Avalanche Forecast

Feb 4th, 2012–Feb 5th, 2012

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

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

Regions: Northwest Inland.

Avalanche danger will peak during the heat of the day.

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Expect generally fine weather through the forecast period. Light winds, warm daytime temperatures at alpine elevations and no precipitation.

Avalanche Summary

Large looming cornices are likely to start falling off with warm temperatures and solar radiation. Large slab avalanches that propagate across entire slopes are possible, especially with heavy triggers such as step-down avalanches, cliff-drops, and cornice drops.

Snowpack Summary

Total snowpack depths are well above average or even new record depths for this time of year. Weaknesses within the upper snowpack and the facets and surface hoar buried mid-January, create the potential for large step-down avalanches, but things seem to be settling rapidly.Snowpack tests on the mid-January facets down 80-150cm consistently produce sudden fractures and this weakness seems to be particularly touchy below 1500m where it is shallower and sits on a crust. Weak wind slabs and large fragile cornices are lurking in exposed lee and cross-loaded terrain.

Avalanche Problems

Cornices

Cornices are expected to become unstable with anticipated warm alpine temperatures.

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

Elevations: Alpine.

Likelihood: Likely

Expected Size: 2 - 6

Wind Slabs

Below ridge crests, behind terrain features and in cross-loaded gullies.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 5

Storm Slabs

Facets down 40-60cm may take some time to gain strength. Watch steep slopes, convex rolls, and unsupported slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4