Regions
Banff Yoho Kootenay.
The wind has gotten to high alpine areas, but good ski conditions can still be found in sheltered locations. The hazard will increase on Thursday if the freezing level forecasts come true.
Weather Forecast
A strong high pressure system is building in the region. Winds will ease to light from the NW on Wednesday. Temperatures are rising, and freezing levels are forecast to hit ~1500m on Wed, and 2000 - 2500m on Thursday and Friday. We may see an inversion set up towards the end of this period.
Snowpack Summary
Above 2500m, the surface snow has been blown into windslabs in exposed areas. Below 2500m, 30 -50 cm of snow lies over the Nov 27th and Nov 23rd crusts. Both of these now overly the Halloween crust/ facet layer that sits 30-50cm above the ground. This lower layer is a facet layer above 2500m and a crust below. Some surface hoar is forming below TL
Avalanche Summary
Some small loose dry avalanches were observed in steep terrain triggered by wind on Mt Fairview. Additionally, a couple size two slabs were observed near the Pulpit area on the Icefields Parkway. These were on steep NE facing terrain and likely triggered by windloading and sluffing. .
Confidence
Freezing levels are uncertain on Thursday
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.