The snowpack is still recovering from a warming event this week. Surface instabilities remain likely to trigger, and have a high potential to step down resulting in large, dangerous avalanches.
Make conservative terrain decisions, and avoid overhead hazard.
This avalanche problem is associated with a weak facet and crust layer buried at the end of January approximately 80cm down in sheltered areas. This includes a crust layer formed in early March below the recent storm snow which is prominent on solar aspects.
If triggered, it is possible to initiate lower weaker persistent layers creating a large avalanche.
Avalanches in the upper snowpack are likely to step down to this deeper weak layer.
Road patrols on the icefields Parkway Wednesday observed a widespread wet loose cycle to size 2 in steep terrain on all aspects, triggering persistent and deep persistent slab avalanches in some areas to size 3. Storm slab avalanches were also observed occurring on solar aspects.
New wet loose and slab avalanches continue to be observed, especially at tree line, along the Icefields Parkway through Thursday. Poor visibility into terrain above 2000m.
10-20 cm of new snow is settling quickly. Warm temperatures on Wednesday have resulted in moist surface snow to 2600m. At 2200m the top 80cm remains moist despite cooling temperatures. At treeline and below, the 70-90 cm from earlier in March has settled into a supportive midpack. This bridges a complicated and reactive deep persistent weakness. Where the snowpack is shallow, the bridging is not strong and triggering a large avalanche is very possible.
Friday
Cloudy with scattered flurries. Accumulation: 4 cm. Alpine temperature: High -2 °C. Ridge wind light to 20 km/h. Freezing level: 2000 metres.
SaturdayFlurries. Accumulation: 7 cm. Alpine temperature: Low -8 °C, High -4 °C. Ridge wind south: 10-25 km/h. Freezing level: 1800 metres.
Sunday
Cloudy with sunny periods and isolated flurries. Precipitation: Trace. Alpine temperature: Low -7 °C, High -2 °C. Ridge wind light to 20 km/h. Freezing level: 1800 metres.
