Carefully assess steep lines for wind slabs and limit exposure to cornices. We have some uncertainty in the likelihood of triggering persistent slab avalanches.
Sensitivity to triggering wind slabs could be greater where wind slab has formed over surface hoar or a crust. If triggered, wind slab avalanches have potential to step down to deeper layers.
Limit exposure to cornices. Cornice falls can trigger large avalanches on the slopes below.
We have uncertainty as to whether a layer of surface hoar buried 70-120 cm deep remains a problem. While it is now likely too deep to be easily triggered by riders, it may remain triggerable by large loads such as cornices and avalanches.
Friday night: Possibility of light flurries bringing trace amounts of new snow with light east winds. Low of -2 at 900 m.
Saturday: Flurries bringing around 5 cm. Light to moderate southeast wind. Freezing level 1100 m.
Sunday: A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Light variable winds. Freezing levels rising to 1400 m.
Monday: Sunny with no new snow expected and light west winds. Freezing level rising to 1500 m.
On Thursday a size three natural persistent slab avalanche was reported . This avalanche ran on the mid March surface hoar layer. It was at 1600 m on a northeast aspect. Several natural and explosive triggered cornice falls up to size three were also reported throughout the region. Natural and explosive triggered wind slabs were observed to size 1.5.
Touchy avalanche conditions on Wednesday saw skiers and machines remotely triggering storm slabs size 1.5-2. We're scratching our heads over a report from near Ningunsaw of a skier-triggered size 2.5 and sympathetic size 2 deep persistent slab. The avalanches occurred on a west aspect around 1200 m and crown depths varied from 40 cm to 120 cm.
30-50 cm of recent snow has seen variable wind effect at upper elevations. Below 1500 m, recent snow tapers in depth and sits over a wet or crusty upper snowpack.
A weak layer of surface hoar from mid March buried 70-120 cm deep has become more difficult to trigger but recent avalanche observations indicate that it may continue to be problematic.
A thick rain crust from mid-February 130-200 cm deep caps a well consolidated lower snowpack.
