Archived

Avalanche Forecast

Apr 6th, 2013–Apr 7th, 2013

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

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 Coastal.

Confidence

Fair - Freezing levels are uncertain on Sunday

Weather Forecast

Overnight and Sunday: Moderate precipitation is expected to continue this evening, becoming light convective showers by morning. Temperatures should cool down a few degrees as the precipitation ends.Monday: A ridge of High pressure is expected to start to dry up the region on Monday. There is a chance that a low pressure system that is tracking South of the U.S. border may alter its course and cause enhanced precipitation for the Southeast regions.Tuesday: High pressure is expected to bring mostly clear skies and light winds during the day.

Avalanche Summary

No new reports of avalanches.

Snowpack Summary

10-15 cm of new snow sits on a variety of old snow surfaces including a melt-freeze crust, moist snow, sugary facets, and wind affected snow. Pockets of wind slab could develop in exposed lee terrain over the next several days. Between 50-75cm below the surface is layer of surface hoar buried on March 9th which is variably reactive. In some areas it is stubborn and requires a significant trigger. In other areas the layer is still well preserved showing sudden planar or sudden collapse test results, and remains a primary concern among some professional operators.The mid snowpack is generally well settled and strong. Having said that, basal facets may resurface as a concern with spring warming, particularly in the north of the region. Cornices are large and untrustworthy.

Avalanche Problems

Wind Slabs

New winds slabs may form in exposed lee terrain and cross-loaded features. Triggering may be possible in steep terrain.

Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

Recent reports of remote triggering suggest the March 9th surface hoar layer is still touchy in some areas. Where it is still reactive, avalanches can be large and potentially destructive.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 5

Cornices

Large developed cornices loom over slopes. A cornice fall has the potential to initiate large avalanches.

Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 6