Avalanche Forecast
Issued: Dec 6th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
shorton,
Avalanche Canada
Avalanche danger will gradually increase in wind-affected terrain this week.
Summary
Confidence
Weather Forecast
MONDAY NIGHT: Clear skies, no precipitation, light wind from the west, treeline temperatures around -15 C.
TUESDAY: Increasing cloud with some light flurries in the afternoon, no significant precipitation, moderate wind from the southwest, treeline temperatures warming to -12 C.
WEDNESDAY: 10-25 cm of low density snow, light to moderate wind from the west, treeline temperatures around -12 C.
THURSDAY: Mostly cloudy skies, no precipitation, light wind from the west, treeline temperatures around -12 C.
Avalanche Summary
Avalanche activity over the weekend was limited to a few small dry loose avalanches and one larger wind slab. This avalanche was naturally triggered on a wind-loaded alpine slope northwest of Revelstoke.
Last Thursday and Friday, there were a few very large deep persistent slab avalanches in the northern edge of the region near Blue River and Kinbasket Lake. These avalanches occurred in steep rocky north-facing terrain and failed on a deeply buried crust layer. One of the avalanches was triggered by a cornice collapse.
There is still visible evidence of a widespread avalanche cycle from the Dec 1st atmospheric river.
Snowpack Summary
10-30 cm of low density snow covers a supportive crust which has been found as high as 2400 m. Winds have exposed the crust in open areas and built wind slabs in leeward terrain. Loose snow persists in protected areas and depressions.
The snowpack is generally well-consolidated below the surface crust. The mid-November crust is found down 70-150 cm with some faceting below the crust. This feature disappears above 1900 m and does not appear to be problematic at this point.
Snowpack depths range from 100-250 cm at treeline and above. The snowpack decreases rapidly below 1600 m.
For an in depth look into the recent weather, current snowpack and our thoughts for the future visit the Forecasters' Blog.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Use caution when approaching steep and rocky terrian.
- Wind slabs may be poorly bonded to the underlying crust.
Problems
Wind Slabs
Wind speeds will increase as a weak frontal system crosses the region on Tuesday. The wind will likely form some unstable slabs on the downwind side of ridges. Wind slabs could be poorly bonded to the underlying crust.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 7th, 2021 4:00PM
