Avalanche Forecast
Issued: Dec 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Persistent Slabs and Loose Wet.
mhalik,
Avalanche Canada
Storm slabs are the main problem at upper elevations. Uncertainty remains around the reactivity of some deeply buried weak layers.
Summary
Confidence
No Rating
Avalanche Summary
On Wednesday there were reports from the Shames backcountry of two ski cuts that produced small (size 1) avalanches and one large (size 2.5) naturally occurring slab. See this MIN post for more details from that day.
Looking forward to the coming days there will be potential for more natural and human-triggered avalanches with the stormy and warm forecast conditions.
Snowpack Summary
35-50cm of storm snow has accumulated over the last several days, bonding poorly to a slippery rain crust that formed on Christmas. With forecast high freezing levels and rain, the upper snowpack is likely to be wet and/or crusty. At upper elevations, strong winds from variable directions have likely built reactive slabs on many aspects in open areas and near ridge crests.Two buried surface hoar layers can still be found in isolated areas, buried 75-100 cm, and 120-200 cm deep. The remaining mid and lower snowpack contains several well-bonded crusts. Snow depths are highly variable depending on elevation, and decrease rapidly below treeline.
Weather Summary
Thursday Night
Cloudy. Light to moderate rain: 7mm near Terrace, 15mm near Kitimat, expected with snow above 1500 m and freezing levels climbing to 2200 m. 30-50 km/h southerly winds. Treeline temperatures around 1 °C.
Friday
Cloudy. Light rain 3 mm, freezing levels climbing to to 2300 m. 40 km/h southeast wind. Treeline temperatures around 2 °C.
Saturday
Cloudy. Light to moderate rain 5-10 mm, freezing level around 1650 m. Strong southeasterly wind. Treeline temperatures around 2 °C.
Sunday
Cloudy. No precipitation expected, 25-45 km/h southwesterly winds. Freezing level dropping to 500m and a high of -3 °C. at treeline.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- As the storm slab problem gets trickier, the easy solution is to choose more conservative terrain.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Problems
Storm Slabs
30-50 cm of recent snow is sitting on a slippery rain crust. Recent avalanches on this layer suggest it is not bonding well. Strong variable winds have also been building deeper reactive slabs near ridge crests.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Last week, large avalanches were running on layers of surface hoar that are now buried around 75 - 200 cm deep. Although reactivity seems to have subsided, continue to approach steep open slopes with caution for now.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Loose Wet
Loose wet avalanches will become increasingly likely at elevations where precipitation falls as rain.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Dec 29th, 2023 4:00PM
