Wind Slabs
N
NE
E
SE
S
SW
W
NW
- Alpine
- Treeline
- Below treeline
- Likelihood
- Likely
- Size
- 1–2
Recent moderate to strong wind from the west has created wind slabs in the lee of terrain features.
Avalanche forecast
View on mapPurcells
Dec 19 – 20, 2019Avalanche Canada
Archived · expired 7 years ago
Avalanche danger
Sat
Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
Highlights
Wind has created fresh wind slabs at upper elevations. Weak layers near the base of the snowpack remain a concern in steep rocky terrain.
Avalanche problems
Persistent Slabs
NNEESESSWWNW- Alpine
- Treeline
- Below treeline
- Likelihood
- Possible
- Size
- 2–3
Weak layers near the base of the snowpack remain a concern. Likely trigger points are shallow rocky areas.
Confidence
Moderate - Recent weather patterns have resulted in a high degree of snowpack variability within the region.
Weather Forecast
WEDNESDAY NIGHT: Mostly cloudy, 40 km/h wind from the southwest, alpine temperatures drop to -10 C.
THURSDAY: Mainly cloudy with isolated flurries and up to 5 cm of new snow, 30 km/h of wind from the southwest, alpine high temperatures around -6 C.
FRIDAY: Heavy snow with 10-20 cm in northern parts of the region and 20-30 cm in southern parts of the region, 50-70 km/h wind from the southwest, alpine high temperatures around -2 C.
SATURDAY: Heavy snow with 15-25 cm in northern parts of the region and 20-40 cm in southern parts of the region, 40-60 km/h wind from the southwest, alpine high temperatures around -2 C.
Avalanche Summary
Recent snow has produced several small (size 1) slab and dry loose avalanches (including this MIN report from Tuesday). Surface snow will continue to be reactive in wind affected terrain and in western parts of the region with greater accumulations.
On Sunday there was a report of a size 3 explosive controlled deep persistent slab avalanche on a north aspect in the alpine. The fracture was 150 cm deep. On Monday there were also reports of a few explosives controlled size 1.5 deep persistent slab avalanches on north aspects at treeline.
Snowpack Summary
Wind slabs are forming at higher elevations and anywhere from 15 to 40 cm of recent snow may sit on a weak layer of surface hoar in sheltered areas at treeline. A second layer of surface hoar primarily found in the in north of the region is found 40-60 cm below the surface in sheltered areas at treeline. There are a variety of crusts buried in the mid to lower snowpack. These crusts have mostly broken down. The base of the snowpack generally consists of facets and depth hoar.