Avalanche Forecast

Issued: Mar 27th, 2013 11:06AM

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

mpeter, Avalanche Canada

South Coast.

Avalanche Danger will increase with daytime heating on south and west facing terrain. Be aware of changing conditions.

Summary

Confidence

Good

Weather Forecast

Thursday: There is a slight chance of thin cloud developing with isolated flurries. Winds should be calm with alpine temperatures reaching 2.Friday & Saturday: Expect mostly clear skies, light southerly winds and alpine temperatures reaching 5 in the afternoons.

Avalanche Summary

Loose wet avalanches up to 2.0 have been reported on solar aspects.

Snowpack Summary

Recent warm temperatures have created melt freeze crusts up to 2000m on all aspects and well into the alpine on south and west facing terrain. These crusts break down with daytime warming and the surface snow can lose cohesion as a result. Cornices are huge!Various melt-freeze crusts are buried in the upper snowpack. In general, the bond at these interfaces is good. A layer of surface hoar (buried on March 11; now down about 60 cm) is still being observed in some locations, with moderate to hard results in snowpack tests. Triggering this layer has become less likely, but possible with a large trigger or from a thin snowpack zone. Mid and lower snowpack layers are well bonded.

Problems

Loose Wet

Daytime warming or solar radiation may cause loose wet avalanches on steep south-facing or low elevation slopes. Wet slabs are also possible, especially on steep low elevation terrain.

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

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Cornices

Cornices are large and lose strength with daytime heating.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 6

Persistent Slabs

Avalanches failing on a crust and/or surface hoar layer buried about 60 cm are becoming less likely, but could be triggered with a heavy load (cornice), or from a thin or convex-shaped part of a slope.

Be cautious of convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Mar 28th, 2013 2:00PM