Warm temperatures are gradually penetrating the snowpack, potentially awakening deeper instabilities.Given the high level of uncertainty in the current snowpack conditions, we advise approaching the alpine, particularly in glaciated terrain, with extra caution. Overhead hazards such as cornices should be on your radar.
Rising temperatures and sun the next few days in combination with the recent snowfall will increase the problem's potential. Be aware of the potential for loose wet or dry avalanches in steep terrain where snow hasn't bonded.
Recent snow and wind has formed isolated windslabs in lee areas at ridgetop in the alpine. The winds have been very variable so assess for loading in the not-so-normal locations.
Freezing levels are supposed to rise on Sunday. There is a lot of uncertainty in the reactivity and likelihood of the basal layer being triggered, however, the last three days have seen warm temperatures penetrating deeper in the snowpack and this may tickle the deep instabilities in the snowpack.
Jasper Visitor Safety received a second hand report of a very large slab avalanche, triggered by a cornice fall. This avalanche took place in steep glaciated terrain near Columbia Icefields and scrubbed to glacial ice with crown as deep as a few meters. Icefields parkway patrol noticed a few large wet slabs on west aspects in the Alpine. the slabs were running on old sun crusts and were most likely running within the new snow. Widespread small loose wet cycle noted in the area.
Last weeks snow melting away below tree line and amalgamating with old snow elsewhere due to warm temperatures. Below, cornucopia of crusts up to 2600m, all aspects, and mountain top on solar aspects. Average height of snow 50-100cm. Below tree line is below threshold.
Mountain Weather Forecast is available at Avalanche Canada
Sunday:
Sunny with cloudy periods. Precipitation: Nil. Alpine temperature: High 5 °C. Ridge wind light to 15 km/h. Freezing level: 2800 metres.
