Avalanche Forecast
Issued: Jan 31st, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
llarson,
Avalanche Canada
Wind slabs continue to be triggered by riders in this region. Watch for wind-affected snow as you transition into open terrain features on all aspects at treeline and alpine elevations.
Summary
Confidence
Moderate
Avalanche Summary
On Monday, skier-triggered wind slabs, up to size 1 were reported from steep terrain features.
On Sunday, a few natural loose dry avalanches were reported up to size 1.5 in steep terrain.
On Saturday, explosives control produced wind slab avalanches to size 2 on southern aspects. Several size 1 wind slab avalanches, triggered by skier traffic, were reported throughout the region. A few size 1 natural loose dry avalanches were observed in steep terrain.
Thank's for all the MIN's! Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Recent snow continues to be redistributed by variable winds at alpine and treeline elevations. On steep southerly aspects, snow sits above a melt-freeze crust while on northerly aspects it overlies previously wind-affected surfaces.
Several weak layers are found mid-snowpack. A surface hoar layer from early January is found down 40-80 cm. Observations suggest that this layer is slowly rounding. If preserved it would be found in sheltered and shaded terrain features.
A thick melt-freeze crust from Boxing Day is buried 70-100 cm deep. This layer is helping to cap lower snowpack weaknesses but at higher elevations, this crust is thinner and less supportive.
The lower snowpack contains weak and faceted grains. Professionals continue to monitor weak layers in the snowpack however they are not active avalanche problems at this time. Avoid shallow, rocky areas where snowpack transitions from thick to thin and triggering weak layers is more likely.
Weather Summary
Tuesday Night
Mostly cloudy and isolated flurries, trace accumulation. Southwest ridgetop winds 10 - 15 km/h. Treeline temperatures -10°C.
Wednesday
Mainly cloudy, with 5 to 10 cm accumulation. 10 to 20 km/h ridgetop winds. Treeline temperatures high -6°C
ThursdayPartial clouds, no new snow, increasing southerly winds 15 to 30 km/h, treeline temperatures high -5°C
FridayMostly cloudy, 10 cm new snow, 10 km/h southerly winds, treeline temperatures high -3°C
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Approach lee and cross-loaded slopes with caution.
- Wind slabs may be poorly bonded to the underlying crust.
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
Problems
Wind Slabs
Wind slabs are found at treeline and alpine elevations. Moderate winds have varied creating widespread wind affect at higher elevations throughout the region.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A persistent weak layer of surface hoar is buried 50 to 70 cm down. This depth is prime for human triggering. Buried surface hoar is more likely to be preserved in terrain features protected from wind and sun effect.
The lower snowpack is comprised of weak, faceted grains and can be triggered under the right circumstances. Be especially suspicious of shallow, rocky, or cross-loaded areas with variable snow depths.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 1st, 2023 4:00PM
