A complex snowpack has led to several recent avalanche incidents, including a fatal avalanche near Pemberton. Clues of instability may not be obvious, so stick to low-angle terrain at all elevations and avoid overhead hazard.
Wind loaded pockets below ridge crests and rollovers may be reactive to human triggers. Watch for localized reverse-loading on south-facing slopes due to recent northerly winds.
Weak layers of surface hoar and/or faceted grains may be found above a hard melt-freeze crust. Recent reports suggest the weak layers may be less prevalent in the south of the region, but still exist in localized pockets.
TUESDAY NIGHT - Flurries, 5-10 cm / southwest wind, 20-40 km/h, gusting to 80 km/h / alpine low temperature near -4
WEDNESDAY - Flurries, 5-10 cm / southwest wind, 40-60 km/h, gusting to 80 km/h / alpine high temperature near -2
THURSDAY - Mainly cloudy / light southwest winds / alpine high temperature near -3
FRIDAY - Flurries, 5-10 cm / southwest wind, 30-50 km/h gusting to 75 km/h / alpine high temperature near -2 / freezing level 1500 m
There was a fatal avalanche north of Pemberton in the Goat Peak area on Monday. This avalanche resulted in two fatalities. It was reported to be a size 2.5 persistent slab avalanche on a west aspect, around 1650 m. The RCMP press release can be viewed here.
A size 2 avalanche was triggered on Monday by a skier in alpine terrain on Mt. Matier along the Duffey. The avalanche occurred on a northwest aspect and was likely a wind slab avalanche. It carried the skier over cliffs resulting in several minor injuries. Numerous smaller (size 1) skier triggered avalanches were also reported around the Duffey.
A size 1 wind slab avalanche was reported from an east aspect on Cayoosh on Sunday. Storm slabs and loose dry avalanches were also reported from Chief Pascal on the Duffey and on the Yak/Nak col along the Coquihalla.
A few persistent slab avalanches were reported last week, mostly in the north of the region near the Hurley, but also near Allison Pass. They were triggered by riders, heavy machinery, and naturally. The slabs were generally 60 to 90 cm deep, around 2000 m, and released on the weak layers described in the snowpack summary.
15-25 cm of recent snow has seen some redistribution by wind, resulting in good riding quality on lee aspects in the Coquihalla area, according to the great MIN reports we've received. (If you're going out in the Duffey, please share your observations on the MIN!) Below treeline, recent snow may be sitting over surface hoar.
A hard melt-freeze crust from early December is found around 40 to 120 cm deep in the snowpack. This crust may have weak layers above it, consisting of feathery surface hoar or sugary faceted grains. These weak layers are most prevalent in the north (e.g., Duffey Lake, Hurley) and found to a lesser extent in the south of the region. The snowpack should be treated as suspect anywhere you find either surface hoar or faceted grains above the crust.
The remainder of the snowpack is well-settled in the south of the region. In the north, another melt-freeze crust with associated faceted grains around it may be found near the ground. Without evidence of recent avalanche activity, the layer appears to be dormant at this time.
