Avalanche Forecast
Issued: Dec 13th, 2018 4:03PM
The alpine rating is Storm Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Friday
Weather Forecast
THURSDAY NIGHT: Light snow, 2-4 cm.FRIDAY: Sunny. Strong southwesterly winds. Freezing level around 1800 m. Light snow Friday night.SATURDAY: A mix of sun and cloud. Winds becoming light to moderate southwesterly. Freezing level around 900 m.SUNDAY: Flurries. Freezing level rising to around 1800 m. Moderate or strong southwesterly winds.
Avalanche Summary
Reports from the Fernie and Corbin areas on Wednesday showed numerous storm slab releases, both natural and explosives-triggered. Slabs ranged from 20-80 cm in depth, depending on wind effect, with sizes generally from size 1.5-2. Size 2 would be classified as 'large'. These all occurred from about 1700-2000 metres and were focused on north to east aspects due to strong southwest winds.Another recent notable avalanche was a size 2 human triggered avalanche on December 2nd in Cornice Bowl north of Fernie. It occurred on a northwest facing feature at 2300 m and ran on a crust layer. There are good photos in this MIN report.
Snowpack Summary
Around 40 cm of new snow has fallen in this region. The new snow has buried an old snow surface that was noted earlier in the week for a cover of large, weak surface hoar crystals as well as hard wind slab and some sun crusts. Beneath the new snow and old surface, the snowpack has been stuck in early season conditions, hovering at roughly 100 cm of depth in alpine areas and much less at lower elevations. See the snow profile in our field team's MIN report for a visual representation of the pre-storm snowpack here. Aside from storm slabs now blanketing the surface, a primary concern is the combination of weak facets and crusts in the bottom half of the snowpack. The crust is most prevalent at and above treeline and is likely most problematic on north-facing features, especially those that are large and planar in nature. A layer of large surface hoar can also be found at similar depths in some areas, as found in a recent MIN report here.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 14th, 2018 2:00PM