Archived

Avalanche Forecast

Jan 16th, 2014–Jan 17th, 2014

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

4: High

The avalanche danger rating in the alpine will be high

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

Regions: Glacier.

Don't let the sun lure you into letting your guard down. Strong solar and warm alpine temps are expected to increase avalanche danger. Avalanches from solar aspects may run full path to valley bottom. Cornices may fail, triggering deep layers.

Weather Forecast

A strong ridge of high pressure will bring lots of sun (adding solar radiation to the snowpack) through the weekend. In addition, a strong temperature inversion is developing. Above freezing temps are expected up to 2500m today, and 3000m on Friday. Moderate SW winds at treeline will ease to light, with strong NW winds loading slopes at ridgetop.

Snowpack Summary

Over a meter of new snow from the last week is settling. It sits on a surface hoar/graupel layer. Strong SW winds have formed slabs in exposed areas at all elevations. Rain below 1300m formed a crust. The mid pack is well settled with the Nov28 surface hoar layer down around 2m where present. The facetted base is showing signs of strengthening.

Avalanche Summary

Avalanches yesterday were from steep terrain, including a size 3. On Mon, over 62 natural and 47 artillery controlled avalanches occurred along the highway. Most size 2.5-3.5. A size 3.5 natural from Dispatchers Bowl traveled 400m down Connaught creek. Artillery triggered a size 4.0 off Mt Green that failed to glacial ice & ran onto the highway.

Confidence

Avalanche Problems

Storm Slabs

Over a meter of new snow is about to get hit by lots of solar and above freezing temps right up to mountain top. Natural avalanches are expected from steep, solar aspects. In addition, the storm slab will likely be more reactive on sun exposed slopes

Avoid exposure to solar aspects overhead, large avalanches may reach the end of run out zones.Minimize exposure to sun exposed slopes when the solar radiation is strong.

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

Elevations: All elevations.

Likelihood: Likely

Expected Size: 2 - 3

Wind Slabs

Strong winds have formed windslabs in open areas at all elevations. In many areas they formed over lower density snow, which may be triggerable. Be especially cautious in places where even small avalanches can have high consequences, ie over cliffs.

Be cautious as you transition into wind affected terrain.Watch for areas of hard wind slab in steep alpine features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

The recent avalanche cycle showed the reactivity of the snowpack to rapid loading and its capability to produce large avalanches. Likely triggers are cornices failing and other avalanches stepping down. Be cautious in areas that have not avalanched.

Be aware of thin areas that may propogate to deeper instabilites.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 - Possible

Expected Size: 3 - 4