Regions
Banff Yoho Kootenay.
Last nights up-slope storm dropped up to 20cm on the southern and eastern areas of the forecast region with little to no wind. Great skiing to be had, but watch for hidden rocks and give any older windslabs some time to settle.
Weather Forecast
We are under the influence of a ridge of high pressure until Friday. Tuesday will be a great day to be in the mountains with light winds, sunny skies and a good freeze. Wednesday and Thursday will have weaker freezes and potentially cloudier skies, but light winds and no precip.
Snowpack Summary
5 - 20 cm's of new snow with light E winds from last night overlies a variety of old surfaces. Northern and western areas received less snow than Southern and Eastern areas. This new snow overlies isolated windslabs in the alpine and at treeline from Saturday PM's warm/ windy storm. Below 1900m, surface crusts exist as long as temps stay cool.
Avalanche Summary
Some small wind slabs reacting to ski cuts and explosives but nothing larger than size 1.5.
Confidence
The weather pattern is stable
Problems
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.