Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural and human triggered avalanches likely.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Regions
Banff Yoho Kootenay.
A juicy storm is forecast to arrive and we are expecting a widespread avalanche cycle Monday/ Tuesday. Now is a good time to stay out of avalanche terrain!
Weather Forecast
Rising temps, increased winds and up to 30 cm of snow Monday and overnight into Tuesday will likely cause a natural avalanche cycle if the current forecast comes true. Tuesday and Wednesday the temps will cool, and the winds will die, but we are still expecting another 10-20 cm.
Snowpack Summary
Alpine winds have created wind slabs in leeward areas up to 1m thick. 25-55 cm of settled snow from recent storms has formed a soft slab over 3 persistent weak layers of surface hoar and facets in the upper half of the snowpack: Jan 16 down 25-45cm; Jan 6 down 35-55cm; and Dec15 down 45-80cm. In snowpits, these layers are giving sudden test results
Avalanche Summary
A size 2.5 natural was observed in the the Sunshine backcountry today. Low visibility meant that fewer new avalanches were observed, but several close calls in the last few days: - size 3 at treeline in Kootenay resulting in a 2.7 m burial who was rescued with no injuries! - size 1.5 near Vermillion peak that buried a skiier to his chin
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.