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
Little Yoho.
Yet another storm system will continue to overload the highly sensitive snowpack. Avoid all avalanche terrain. This includes the runout zones of any avalanche path as we have seen avalanches run to valley bottom.
Weather Forecast
Another storm will track through our region starting Wed night and will continue into Thursday. With this we can expect 25-35cm, strong W winds, and temperatures in the -8C range in the alpine. As the storm ends tomorrow, winds will shift to the East and diminish with a cooling trend.
Snowpack Summary
Storms from the last 7 days have deposited up to 70-80cm of snow. The main concern continues to be the 3 persistent weak layers of surface hoar and/or facets that are found between 50 and 150cm down in the snowpack. We continue to observe sudden test results, whumphing and large propagations on these layers.
Avalanche Summary
There have been large avalanches every day this week, mainly to size 3 with some larger. Most of these avalanches have been failing on the persistent layers mentioned above, with the odd avalanche going on the ground. Many close calls have been associated with these events.
Confidence
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.