Avalanche Forecast
Issued: Dec 29th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jleblanc,
Avalanche Canada
With these frigid temperatures, be aware that even a small incident may have serious consequences. If you venture out, watch for fresh wind slabs that are likely reactive to riders.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain. Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.
Weather Forecast
A system, approaching from the north, is aiming at the B.C. coast, with the highest moisture (and snow potential) kept along the coastal ranges. Thursday, an arctic ridge of high pressure will re-establish itself, leading to another clear and cold day heading into Friday. The next round of snow is expected Saturday.
WEDNESDAY NIGHT: Light snow 3-5 cm / Strong northwest winds in the alpine/ Low of -15/ Possible inversion with -8 at 1500 m.
THURSDAY: Flurries / Moderate north winds in the alpine / High of -15 / Possible inversion with -8 at 1500 m.
FRIDAY: Cloudy with snow beginning in the evening/ Light southwest winds in the alpine/ High of -15 / Possible temperature inversion with -8 at 1500 m.Â
SATURDAY: Snow 15-30 cm / Strong to extreme southwest winds in the alpine/ High of -10
Avalanche Summary
A skier accidental (size 1) avalanche was triggered Tuesday on a northwest feature at treeline.Â
Explosives triggered numerous large wind slabs (size 2) on alpine lee North-facing slopes.
If you go out in the mountains, please consider filling out a Mountain Information Network report.
Snowpack Summary
New snow and wind forecasted for Wednesday night will have formed fresh and reactive wind slabs at treeline and alpine. This new snow might be enough to reload some scoured surfaces on east aspects.
Another weak layer of surface hoar layer was buried recently, but it does not seem a problem yet.
The December 18th surface hoar/facet layer is down 40cm, the surface hoar was observed up to 12mm in both the treeline and below. It is likely only a concern in isolated locations in the treeline where wind slab has formed above it.
Snowpack depths vary greatly across the region, expect to find anywhere from 120-300 cm of snow around treeline.
Terrain and Travel
- Avoid freshly wind loaded terrain features.
- Seek out wind sheltered terrain below treeline where you can avoid wind slabs and find great riding.
- Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
Problems
Wind Slabs
New wind slabs could form throughout the night on Wednesday on easterly aspects. These new slabs will likely be reactive to skiers but limited in size. As wind shifts, expect pockets of wind slabs to develop behind all terrain features in the alpine and in open areas at treeline. Sensitivity to triggering will be greatest near ridge crests and at treeline and below where wind slab has formed above the December 18th surface hoar layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 30th, 2021 4:00PM
