Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Regions
Banff Yoho Kootenay.
The danger has been reduced to considerable, however human interaction with avalanches is still very likely on steep terrain and terrain uniform features.Our Wx stations are currently down, we are working on getting them back online ASAP.
Weather Forecast
A slight cooling and clearing trend is expected for Monday. The wind is also expected to die down and shift to the west. However, the moment of respite will be short lived. Another storm is expected to arrive midday on Wednesday bringing warm temps, precip and an increase in wind. We expect the danger to rise significantly at that time.
Snowpack Summary
Up to 40cm of storm snow (48hrs) and strong wind have created slabs that are primed for human triggering. The main concern in the snowpack continues to be the 3 persistent weak layers of surface hoar and/or facets that are found between 50 and 100cm down. We continue to observe sudden test results, whumphing and large propagations on these layers.
Avalanche Summary
Natural activity was directly observed across Bow Lake today. A cornice released off of a cliff and triggered the slope below it, size 2. An avalanche control operation produced 3 size 3 avalanches on West facing avalanche paths on 93N. The debris ran to mid run out. Additionally, evidence of a widespread cycle up to size 3 was observed.
Confidence
Due to the quality of field observations on Monday
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.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.