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
Banff Yoho Kootenay.
The conditions remain tricky. Conservative terrain choices are essential to manage the hazard. The quality of the overnight freeze and amount of solar radiation are big factors to watch for right now.
Weather Forecast
The warm weather we have been seeing the last few days is slowly coming to an end. We should get a better freeze Thursday night with temperatures dropping to -5 / -10 at valley bottom. On Friday, we should get a small pulse of snow (5-10cm's) with moderate SW winds and freezing levels to ~1800m. Saturday looks cooler with light precipitation.
Snowpack Summary
A 50-100 cm slab overlies the January 6th weak layer of surface hoar, facets and sun crust and snowpack tests indicate an unstable bond between the two. The lower snowpack is facetted and quite weak. Warm temperatures over the past 72 hours have triggered an avalanche cycle and left the surface snow affected by sun, temperature & wind crusts.
Avalanche Summary
There have been many large natural and explosive triggered avalanches in the last few days triggered by warm temperatures and solar radiation. A very close call on Twin Cairns in the Sunshine backcountry yesterday - a size 2.5 accidentally triggered took a skiier for a ride and partially buried the skiier.
Confidence
Freezing levels are uncertain on Friday
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.