Rain events will increase the avalanche danger. On Saturday avalanche control and road closures between Parker Ridge and the Weeping Wall will occur from 4:00-8:00 PM. The Maligne Lake road may also be closed on Saturday.
Weather Forecast
Warm overnight temps and cloudy skies will prevent the snowpack freezing solid overnight. Temperatures will remain warm on Friday with the freezing level reaching 2,000m. Up to 15mm of rain may arrive in the afternoon with snow at higher elevations. We expect amounts to vary across the range with convective activity.
Snowpack Summary
10-15cm of new snow is sitting on crusts which extend to treeline (TL) on most aspect and higher on sun facing slopes. Beneath the crusts moist snow extends to close to TL where the snowpack depth is 130-180cm. The midpack is well bonded and warm. The base of the snowpack is weak. Loose snow plasters the steep rock faces. Cornices are large.
Avalanche Summary
On the 17th avalanche activity was noted in the Icefields area. Several deep slab avalanche to size 2.5 from the alpine ran close to the valley bottom. These seem to have been triggered by sluffing from rocky terrain above. Below treeline and in the valley bottom there were several size 1-2 moist point release avalanches which scrubbed to ground.
Confidence
Intensity of incoming weather systems is uncertain
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.