Avalanche Forecast

Issued: Jan 1st, 2018 4:09PM

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

Avalanche Canada mgrist, Avalanche Canada

Pockets of reactive wind slab remain a concern for wind-exposed alpine and tree line areas.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Isolated flurries with a mild inversion for the week as temperatures gradually warm up. Snow on Thursday. TUESDAY: Cloudy with some flurries (2-5 cm possible). Ridge wind moderate south west. Temperature -3. Freezing level 500m with an AFL from 1200m to 1700m. WEDNESDAY: Cloudy with isolated flurries. Ridge wind moderate from the south. Temperature -2. Freezing level 500m with an AFL from 1100m to 1900m. THURSDAY: Snow. Accumulation 10-15 cm. Ridge wind strong from the south. Temperature -2. Freezing level 600 m.

Avalanche Summary

No new avalanches observed.

Snowpack Summary

Only about 5cm of new snow fell as we woke up to a new year. Cold temperatures and strong winds (from a wide range of directions) have affected the surface snow over the past week, scouring some slopes down to an old crust and forming hard deposits in many other areas. There are some lingering wind slabs, found on a variety of old surfaces including a thick melt-freeze crust that formed in mid-December. Cornices have also been noted at ridge tops, lee (downwind) to strong north east winds last week. In non-wind affected terrain, 20-40 cm of unconsolidated (aka faceted or 'sugary') snow overlies the mid-December crust layer. This snow has been sluffing in steep terrain.Beneath the mid-December crust the snowpack is reported to be generally strong with the possible exception of areas around Stewart and northern parts of the region where the late-October, basal crust can be found near the base of the snowpack. Weak sugary snow may exist around this basal crust and could be triggered from shallow snowpack areas.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs may be lingering around ridge crests, exposed gullies and cross-loaded slopes. These wind slabs may be poorly bonded to the buried mid-December crust layer and reactive to human triggers such as a skier or rider.
Watch for whumpfing, stiff or hollow sounding snow, and shooting cracks.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 2nd, 2018 2:00PM