The tail end of a pineapple express will cross the South Coast on Sunday keeping the avalanche danger at HIGH. Travel in avalanche terrain is not recommended.
Summary
Confidence
Fair - Due to limited field observations
Weather Forecast
A strong pacific frontal system will continue to bring heavy precipitation and strong winds to the region through Sunday morning. Clearing and cooling are expected by mid afternoon as a ridge of high pressure moves into the area. The freezing level should drop from 1800-2000m in the morning to 700m late in the day. Monday should be mainly dry with a freezing level around 600-800m. There is a chance of light snowfall on Tuesday with a freezing level around 800m.
Avalanche Summary
Recent control work produced several explosive triggered slab avalanches up to Size 3. Most of these avalanches involved the recent storm snow, but some stepped down to a facet/crust layer near the base of the snowpack. One Size 2.5 avalanche occurred in an avalanche path that had recently released. It reloaded and failed again on the facet/crust interface. Avalanche activity is expected to continue on Sunday with the potential for very large and destructive avalanches.
Snowpack Summary
Recent strong and shifting winds have created a variable snow surface and pockets of deep and dense wind slabs in exposed areas. Fluctuating freezing levels and heavy precipitation will likely produce various storm snow weaknesses. There is a persistent weakness of facets associated with a crust around 40-70cm above the ground. This weakness exists at treeline and alpine elevations and has been sensitive to human triggers. Several recent avalanches on this interface have shown very wide propagation and there have been cases of triggering from a distance. In some areas there is also a factet/crust layer just above the ground. This layer may still be a concern in areas with smooth underlying ground.
Peter,
Avalanche Canada
