Warm temperatures and new precipitation have resulted in a touchy snowpack that will remain triggerable to human traffic into Thursday evening.
Shallow surface instabilities are likely to step down to layers deeper in the snowpack resulting in large avalanches.
This avalanche problem is associated with a weak facet and crust layer buried at the end of January approximately 70cm 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, expect to initiate lower weaker persistent layers creating a large avalanche.
Most active from steep rocky terrain, may overload and trigger the slopes below.
Road patrols on the icefields Parkway 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, as Storm slab avalanches were also observed occurring on solar aspects. Poor visibility into terrain above 2000m.
Warm temperatures on Wednesday have resulted in moist surface snow to 2600m. 10-20 cm of new snow is settling quickly.
In the alpine, SW winds have redistributed snow from earlier in the month. 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.
Thursday
Accumulation: 10 cm. Alpine temperature: High 1 °C. Ridge wind east: 10 km/h. Freezing level: 2200 meters.
Friday
Accumulation: 7 cm. Alpine temperature: Low -8 °C, High -2 °C. Ridge wind south: 10-25 km/h. Freezing level: 1900 meters.
Saturday
Accumulation: 17 cm. Alpine temperature: Low -5 °C, High -2 °C. Ridge wind light to 20 km/h. Freezing level: 1900 meters.
