Avalanche Forecast
Issued: Mar 20th, 2017 4:55PM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
Tuesday: Mainly cloudy with scattered flurries bringing approximately 5 cm of new snow, beginning in the afternoon. Light to moderate east winds. Freezing level to 900 metres with alpine temperatures around -3.Wednesday: Cloudy with flurries bringing approximately 10 cm of new snow over the day. Light to moderate south winds. Freezing level to 800 metres with alpine temperatures around -4.Thursday: Continuing flurries bringing approximately 5 cm of new snow over the day. Light to moderate south winds. Freezing level to 900 metres with alpine temperatures around -3.
Avalanche Summary
A social media report from Sunday described very touchy cornices in the Wolf's Den area north of Terrace, with remote triggering occurring from as far away as 25 metres. A social media/MIN report from the Exstew area shows a recent Size 3 avalanche that appears to have triggered naturally and quite possibly over the late February weak layer.Reports from Saturday included observations of the evidence of several recent natural Size 2 storm slab releases that occurred at 1300-1400 metres. One natural Size 2 was also directly observed running from a steep unskiable terrain feature as direct result of ongoing wind loading. The above activity took place mainly on north to east aspects, highlighting the recent change in wind direction.A report from Thursday included several observations from the north of the region, where skier traffic triggered a Size 2.5 wind slab as well as a Size 2 persistent slab over the late February interface down 50 cm. The large wind slab release was triggered from a thin spot and had a crown fracture that ranged from 30-100 cm. This activity took place on north to northwest aspects.
Snowpack Summary
Clear skies have formed sun crust at the surface on solar aspects over much of the region. Below the surface, last week's stormy weather delivered approximately 40-70 cm of new snow over the week. Winds since the storm have been shifting between southeast and southwest, redistributing this snow into touchy wind slabs on a range of aspects at higher elevations. Recent observations have described a touchy rain crust layer buried approximately 40 cm deep within the storm snow. At treeline and above, new snowfall and wind loading have been stressing a weak interface from late February composed of facets, crust, and surface hoar buried over a metre deep. Recent reports suggest that this layer may remain active in the south of the region. It is substantially more active and presents a more serious concern in the north of the region. A non-supportive surface crust has formed over moist or wet snow at 1100 metres and below.
Problems
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 21st, 2017 2:00PM