Avalanche Forecast

Archived

Jan 5th, 2014–Jan 6th, 2014

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Sea To Sky.

Confidence

Fair - Timing of incoming weather systems is uncertain on Wednesday

Weather Forecast

Monday: Winds becoming moderate Southwest overnight. High cloud with sunny periods in the morning becoming mostly cloudy in the afternoon. A layer of warm air that may be above freezing is expected to sit at alpine elevations until early Tuesday morning.Tuesday: Moderate Southwest winds and light precipitation with freezing levels dropping down to about 1000 metres near the coast and 500 metres inland.Wednesday: The next Pacific system is expected to move onto the coast. Models disagree on the timing and intensity of this next system.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

Reports of surface hoar and near surface facets growing over the past few days. Suspect that the sun and warm alpine temps will destroy these crystals on solar aspects, but these crystals may stay around long enough on shaded aspects to get buried this week by the next storm. Northerly outflow winds have stripped north aspects and developed sastrugi waves in open terrain. Forecast Southerly winds may strip South aspects if the warming leaves any snow available for transport, or press recently deposited snow into stiffer wind slabs. Buried surface hoar and/or a thin rain crust have been reported buried down about 40 cm in the West and South of the region. There continues to be concern for weak basal facets in isolated shallow rocky snowpack areas. Forecast warm alpine temperatures may release weak cornices or loose moist snow from steep solar exposed aspects. Early season riding hazards such as rocks, stumps and logs are lurking below the surface in many areas. In glaciated terrain open and poorly bridged crevasses are everywhere.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.