Wind Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1–2
Recent wind has formed isolated pockets of wind slab in lee features such as ridgetops and gullies.
Avalanche forecast
View on mapNorth Columbia
Dec 11 – 12, 2019Avalanche Canada
Archived · expired 7 years ago
Avalanche danger
Fri
Sat
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Highlights
Don't underestimate the potential for human triggered avalanches. Keep your guard up especially as you transition into wind exposed terrain, and evaluate conditions before committing to larger features.
Avalanche problems
Persistent Slabs
NNEESESSWWNW- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 1.5–2.5
This weak layer formed in late November may present as surface hoar, a crust, facets or a combination, depending on elevation and aspect. It is buried 70-120 cm below the surface and can most likely be found in areas sheltered from the wind, but open to a view of the sky, such as near treeline.
Avalanche Summary
Although natural avalanche activity has largely subsided, natural persistent slabs are still being reported, up to size 2.5 on south aspects. On Monday, a variety of artificially triggered avalanches, up to size 2, were reported on northeast aspects. One explosive controlled avalanche was triggered in a wind slab and stepped down to the persistent weak layer further down the track.
Weather Forecast
Tuesday Night: Cloudy with scattered flurries accumulating up to 5 cm in some areas, alpine low -10, light to moderate southwest wind.
Wednesday: Cloudy with flurries accumulating to 5 cm in the southwest of the region, alpine high -5, light to moderate southwest wind increasing overnight.
Thursday: Periods of snow accumulating 5-15 cm, alpine high -5, strong southwest wind easing to moderate.
Friday: Flurries accumulating to 5 cm in the south of the region, alpine high -5, light west wind.
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Snowpack Summary
Last week's storm snow has seen some redistribution by the wind. Isolated soft wind slabs can be found in the lee of features such as ridge tops. Below the 50-90 cm of snow from last week, a thick layer of faceted crystals, previously wind-affected surfaces, and/or surface hoar in sheltered areas (around treeline and below) is now 40-80 cm below the surface. The surface hoar layer within the storm snow can still be found in some locations but has not shown recent reactivity.
A weak layer formed in late November is now buried 70-120 cm below the surface. This is the layer of concern relating to the persistent slab avalanche problem. The weak layer may present as surface hoar, a crust, facets or a combination, depending on elevation and aspect. It can most likely be found in areas sheltered from the wind, but open to a view of the sky, such as near treeline. Below this, variety of crusts from late October are buried deeper in the snowpack.