Archived

Avalanche Forecast

Feb 3rd, 2017–Feb 4th, 2017

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

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.

The probability of triggering an a full depth avalanche has lowered but the consequence of doing so remains High. Click here for more information in our blog on this specific problem.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Saturday: Sunny with cloudy periods / Moderate east wind / Alpine temperature -20Sunday: Sunny / Light to moderate east wind / Alpine temperature -21Monday: Mix of sun and cloud / Light to moderate east wind / Alpine temperature -20More details can be found on the Mountain Weather Forecast.

Avalanche Summary

There is no recent avalanche activity to report over the last 3 days. However, it is still possible to trigger an avalanche on deeper weak layers at upper elevations either from a thin spot or a smaller avalanche stepping down.

Snowpack Summary

Last weekend's snowfall sits above a rain crust up to about 1300 m in many parts of the region. At tree line and above, the storm snow is settling and/or being redistributed into new wind slabs. Below, several buried surface hoar layers can be found, between 50-100 cm deep. Reports from last week indicate these layers had been yielding moderate to hard results in snowpack tests. A generally stiff mid pack sits above weak sugary snow near the ground. The new load from last week reached a critical level and woke up a deep persistent slab problem in many parts of the region. Currently the probability of triggering an avalanche on those deeper layers has lowered but the consequence remains high. It is still a good time to be cautious and disciplined with terrain choices at upper elevations.

Avalanche Problems

Deep Persistent Slabs

Last week's snow and wind have added a critical load to weak, sugary snow at the base of the snowpack and potential exists for full depth avalanches. This problem may be more acute in lower snowpack areas.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4

Wind Slabs

Moderate to strong winds have formed wind slabs in lee areas. Surface avalanches may also step down to deeper, more destructive layers.

Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2