Archived

Avalanche Forecast

Feb 26th, 2013–Feb 27th, 2013

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

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: South Coast.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Thursday

Weather Forecast

Wednesday: Light flurries with another 3-5cm throughout the day, light to moderate southwesterly winds and freezing levels as high as 1200-1400m. Thursday: Continued light flurries before a warm and wet frontal system makes landfall sometime in the afternoon. Friday: Moderate to heavy snowfall, particularly in the Coquihalla area, with strong southwesterly winds and freezing levels as high as 2000m.

Avalanche Summary

Recent reports include numerous Size 1.0-2.5 natural dry loose and soft wind slab avalanches throughout the region.

Snowpack Summary

Light snowfall on the Duffey and heavy snowfall on the Coquihalla has been redistributed into wind slabs at treeline and above. Surface hoar, facets, and/or crust buried early last week is now around 70cm deep, depending on the area, and remains particularly touchy at treeline. Fresh wind slabs, buried wind slabs, and recent storm snow weaknesses within the top metre are highly reactive to human triggers and have the potential to step down to this persistent weakness, or deeper to another persistent weaknesses buried earlier in the month. Cornices are also large and unstable.

Avalanche Problems

Storm Slabs

New and recent storm snow is expected to become very touchy with continuous loading throughout the forecast period, especially where wind-loaded. Thinner slabs failing within the recent storm snow may step down to old snow surfaces from last week.

Choose well supported terrain without convexities.>Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>Give cornices a wide berth when travelling on or below ridges.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 5

Persistent Slabs

An assortment of persistent weaknesses lurk in the top 100cm. Most notably is surface hoar buried early last week as well as the week before, which are most concerning in sheltered treeline areas.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Remote triggering is a concern, watch out for adjacent slopes.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 4