Avalanche Forecast
Issued: Feb 16th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
shorton,
Avalanche Canada
Heightened avalanche conditions exist on steep convex slopes. Avalanches are less likely where thick crusts exist near the surface.
Summary
Confidence
Weather Forecast
WEDNESDAY NIGHT: Cloudy skies, no precipitation, light to moderate wind from the northwest, treeline temperatures drop to -10 C.
THURSDAY: Cloudy with some isolated flurries bringing trace amounts of snow, moderate wind from the west, treeline temperatures around -3 C with freezing level climbing to 1500 m.
FRIDAY: Mostly sunny, no precipitation, light wind from the west, treeline temperatures around -3 C with freezing level around 1500 m.
SATURDAY: Snow flurries bringing 5-15 cm of snow, moderate wind from the southwest, treeline temperatures around -5 C with freezing level around 1000 m.
Avalanche Summary
Most avalanche activity over the past few days has been small (size 1) human-triggered wind slabs along ridgetops and some small dry loose avalanches. Last week there were several large (size 2-3) persistent slab avalanches reported on the late January surface hoar layer, and this layer has still produced a few small (size 1) human-triggered slabs as recently as Tuesday.
Snowpack Summary
5-10 cm of fresh snow overlies a variety of surfaces. Higher elevations are heavily wind effected with a melt freeze crust on solar aspects. Surface hoar sits below the storm snow in sheltered terrain features.
The late-January interface is buried 20-40 cm deep, and consists of a melt-freeze crust at lower elevations and on solar aspects extending into the alpine. Surface hoar sits above the crust in sheltered areas at treeline and below. This layer is still producing some human triggered avalanches and propagation-likely test results. The mid-January interface is buried 40-60 cm deep, and consists of a crust, facets, and surface hoar.
The snowpack below is well consolidated, with the early December crust/facet persistent weak layer buried 100-200 cm deep. It is currently considered dormant. We expect this layer to become active later this season, check out the forecaster blog for more information.
Terrain and Travel
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Persistent Slabs
Persistent slab avalanches are possible due to two layers of surface hoar found 20 to 40 cm deep. Various combinations of crusts above and below these layers has either made them more or less reactive, resulting in the distribution of this problem being spotty. The problem is less likely in areas with thick and supportive crusts near the surface, but you should be cautions with steep open slopes at treeline, especially in terrain where surface hoar is most likely to be preserved - like cut blocks.
Aspects: North, North East, East, North West.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Small reactive wind slabs are likely found near ridgetops. Slabs could be more reactive where they overlie buried surface hoar or smooth crusts.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 17th, 2022 4:00PM
