Avalanche Forecast
Issued: Feb 4th, 2017 3:40PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
Saturday night: Flurries bringing approximately 10 cm of new snow. Winds moderate to strong from the southwest.Sunday: Flurries delivering another 10-15 cm of new snow. Winds moderate to strong from the southwest. Alpine temperatures around -10.Monday: Flurries and periods of snow bringing 10-20cm of new snow. Winds light from the southeast. Alpine temperatures around -17.Tuesday: Cloudy with sunny periods and isolated flurries with a trace of new snow. Winds light from the west. Alpine temperatures of -15.
Avalanche Summary
Reports from Friday don't yet take our new snow into account, but loose snow sluffing in steep terrain (to Size 1.5) has been a developing theme in recent days, likely aided by faceting of surface snow. Reports from Thursday include details of explosives control in the north of the region producing results up to Size 1, with one cornice result succeeding in triggering a Size 2 slab over our December facet layer.On Monday, several natural wind slab avalanches up to size 2 were observed throughout the region. These avalanches occurred on most aspects and were mainly in the alpine. Since then, skiers and sledders have been triggering several wind slab avalanches up to size 1.5. A MIN report from the Quartz Creek area shows a sledder triggered size 2 wind slab avalanche. Click here for more details. As for Sunday's outlook, fresh storm slabs are expected to be sensitive to human triggering, especially where they overlie weak surfaces and in wind-exposed areas. With this in mind, the potential for storm slab avalanches to 'step down' to deeper weaknesses in shallow snowpack areas should not be overlooked.
Snowpack Summary
New snow over Friday and Saturday has now covered a range of different conditions that existed at our previous surface. In addition to wind slabs that exist on a variety of aspects in wind exposed terrain, the new snow will also overlie a sun crust reported on steep sun-exposed slopes as well as surface hoar recently found growing on sheltered open slopes. Surface faceting was also recently reported as a result of the current cold temperatures. The new snow's bond to these surfaces will likely be weak and touchy conditions can be expected as it settles into storm slabs above them. A persistent weakness buried mid January is now down 30-60 cm and consists of buried surface hoar in sheltered areas, sun crust on south aspects, and/or widespread faceted old snow. It has generally stabilized but may be sensitive to triggering in isolated areas where surface hoar is preserved. Another surface hoar/facet persistent weakness buried mid-December may be found down 600-110 cm, but is generally considered dormant. This and deeper persistent weaknesses remain an isolated concern in shallow snowpack areas where they lie closer to the snow surface.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 5th, 2017 2:00PM