Avalanche Forecast

Issued: Jan 17th, 2013 9:32AM

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

jlammers, Avalanche Canada

Sea To Sky.

Summary

Confidence

Good

Weather Forecast

Mainly clear skies are expected for the forecast period as a static ridge of high pressure continues to dominate the region. For the next 3 days, winds will be mostly light and variable with alpine temperatures hovering between 0.0 and 3.0.

Avalanche Summary

On Wednesday there were reports of a few small loose wet avalanches on steep sun-exposed slopes, and couple of skier-triggered size 1 slab or loose snow avalanches in steep south facing terrain. There were no new avalanches reported on Thursday.

Snowpack Summary

The snow surface consists of thin wind slabs and wind-pressed snow, a sun crust or moist snow, and dry faceted snow or large surface hoar depending on aspect, elevation, and time of day. 40-70cm below the surface is a persistent weakness of surface hoar, facetted snow, and/or a crust buried at the beginning of January. Most recent tests have shown moderate results at this interface with resistent planar fracture characteristics. Although not widespread, this layer seems to be found in portions of sheltered terrain at and below treeline, and may still be fairly well preserved.No significant weaknesses have been reported recently below this in the mid snowpack layers. Near the base of the snowpack, a crust/facet layer exists, which is now unlikely to be triggered, except perhaps by heavy triggers in steep, shallow, rocky terrain where more facetting has taken place.

Problems

Loose Wet

Loose wet activity is expected as temperatures rise. A loose wet slide could step down and trigger weaknesses deeper in the snowpack.

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

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Warm temperatures and solar radiation will increase the probability of avalanches releasing on a buried weak layer of surface hoar, facets, and/or a crust, down 40-70 cm.

Conditions have improved, but be mindful that deep instabilities are still present.>Be aware of the potential for large avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Wind Slabs

Strong variable winds have created thin wind slabs in exposed lee and cross-loaded terrain features.

Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 18th, 2013 2:00PM