Avalanche Forecast

Issued: Dec 24th, 2013 8:28AM

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

jlammers, Avalanche Canada

Sea To Sky.

Summary

Confidence

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

Weather Forecast

Wednesday: Mainly cloudy with flurries / Moderate westerly winds / Freezing level at 1100mThursday: Light to moderate snowfall / Moderate southwesterly winds / Freezing levels at 1600mFriday: Flurries / Light ridgetop winds / Freezing level at 1200mSpecial Notice: Our radar has just picked-up what appears to be a flying sleigh. Our forecasters believe the sleigh belongs to Santa as it is being pulled by at least 8 reindeer. The sleigh is located in the far north of the province at the 2000m elevation and is currently headed south. More information will be posted as it becomes available.

Avalanche Summary

Touchy small windslabs were reported to have been ski cut on Monday. They formed in the immediate lee of ridge crests and reportedly had little propagation. No other avalanches were reported.

Snowpack Summary

Recent snowfall amounts have been highly variable throughout the region with southern areas receiving as much as 25cm throughout Sunday. Strong southwest winds have created pockets of wind slab which have most likely gained significant strength. Roughly 20-45cm below the surface you may find a variety of old surfaces which formed during the early December cold snap. These surfaces include sugary faceted snow (which may overlie a crust in some areas), spotty surface hoar in sheltered terrain, and hard wind slab on south-facing alpine terrain. In most places the more recent snow seems to be well bonded to this interface, but the crust/facet combo was reported to be reactive to skier triggering in the Callaghan/Tricouni area.Snowpack depths vary greatly across the region, but are significantly lower than average for this time of year. Terrain below treeline is still mostly below threshold for avalanche activity. Early season riding hazards such as rocks, stumps and logs are lurking below the surface in many areas. In glaciated terrain new snow on the surface might be just enough to hide open crevasses where supportive snow bridges have not yet developed.

Problems

Wind Slabs

Recent snowfall and strong southwest winds will have created stiff new windslabs in lee terrain. Although they may be gaining strength, they may propagate over wide distances, particularly in the south where recent accumulations were significant.

Be alert to conditions that change with elevation.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Weak crystals overlying a crust have been reported from the south of the region. This spotty yet potentially reactive interface is buried up to about 50cm below the surface and may have the potential to catch riders by surprise.

Make observations and assess conditions continually as you travel.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 25th, 2013 2:00PM