Avalanche Forecast

Issued: Mar 3rd, 2013 9:25AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet and Wind Slabs.

pgoddard, Avalanche Canada

Northwest Coastal.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain for the entire period

Weather Forecast

Monday: Sunny. Light winds. Freezing level around 700 m.Tuesday: Sunny. Light winds. Freezing level around 400 m.Wednesday: Sunny. Light winds. Freezing level around 300 m.

Avalanche Summary

Sunshine and warming have triggered loose avalanches over the last couple of days. Isolated pockets of wind slab have been triggered by skiers. A widespread natural cycle occurred in response to snow and wind-loading on Wednesday/Thursday, with several slabs of size 2-3, and a few in the size 3-4 range. The largest event failed as the entire snowpack on basal facets and was triggered by cornice fall.

Snowpack Summary

About 40-70 cm recent storm snow is showing signs of stabilizing. Recent strong, variable winds left wind slabs at treeline and alpine elevations. Direct sun is weakening the snowpack on sunny aspects during the day. A layer of surface hoar, facets and/or a crust is buried in the upper snowpack, but most operators report a good bond at this interface. Some large cornice falls have been reported over the past few days. Most have not triggered slabs on the slopes below, however one triggered a very large avalanche. The mid snowpack layers are generally well settled and strong. Facets at the base of the snowpack have resurfaced as a concern now that spring is on the doorstep and full-depth releases are becoming more likely.

Problems

Loose Wet

Warm sun is weakening surface snow, particularly on steep sun-exposed slopes. Loose wet avalanches can entrain a surprising amount of mass as they travel.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Wind Slabs

Wind slabs may be found behind terrain breaks. Large fragile cornices are also a concern at the moment.

Use ridges or ribs to avoid pockets of wind loaded snow.>Give cornices a wide berth when travelling on or below ridges.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 4th, 2013 2:00PM