Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
South Rockies.
Jump over to avalanche.ca/blogs to learn more about the persistent slab problem.
Confidence
Poor - Due to the number of field observations
Weather Forecast
Synopsis: Light precipitation is possible Saturday afternoon as a weak system passes over the SE portion of the province. On Sunday a strengthening ridge of high pressure drives cold and dry conditions that will likely persist for the next week. Saturday: Freezing Level: Valley Bottom; Precipitation: 1-3mm | 1-4cm; Wind: Treeline: Moderate, W/SW | Ridgetop: Strong, NW.Sunday: Freezing Level: Valley Bottom; Precipitation: Trace; Wind: Treeline: Moderate NE | Ridgetop: Moderate, NE.Monday: Freezing Level: Valley Bottom; Precipitation: Trace; Wind: Treeline: Moderate, NE | Ridgetop: Moderate, E.
Avalanche Summary
No new avalanche activity to report, but in the neighboring Lizard Range avalanches continue to be human triggered to size 2. If you have any avalanche observations to report, please send an email to [email protected].
Snowpack Summary
Prior to Tuesday nights 15 - 20 cm, generally light amounts of snow have fallen in the last week. In the alpine, winds have been conducive to blowing this snow into wind slabs in exposed lee areas. 30 - 60 cm below the surface (more in wind affected areas) you are likely to find a crust that may have surface hoar on top of it. The crust is reported to extend into the alpine to at least 2100 m; the surface hoar was reported to be most reactive on shady aspects around treeline and just below, between around 1600 m and 1900 m. Where the crust exists, it is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on high alpine slopes above where the rain crust formed, facets, and/or buried surface hoar may be susceptible to triggers.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.