Avalanche Forecast
Issued: Feb 1st, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
bchristie,
Avalanche Canada
Continue to make conservative terrain choices as you gather information after a period of rapid change.
Colder temperatures should increase the strength of the snowpack in the short term.
Summary
Confidence
Moderate
Avalanche Summary
On Thursday, north of Stewart, a small, natural loose wet avalanche and widespread pinwheeling were reported below treeline. We expect this wet instability to be less likely as temperatures drop overnight into Friday.
On Wednesday, large (size 2.5) natural wind slab avalanches were reported in alpine terrain.
Snowpack Summary
The upper snowpack is a mix of wind slabs, moist snow, dry snow, and a frozen crust that exists up to 1800 m.
Around 60-100 cm below the snow surface, a thick crust buried in early January exists up to 1600 m. At higher elevations, this same layer is weak, sugary faceted snow. More weak layers of facets and feathery surface hoar (formed up until mid-January) sit on top of this layer. The recent storm snow/rain and warm temperatures triggered large avalanches on these layers during the height of the storm. It is expected that they will strengthen as the temperature drops.
Below treeline, the majority of the snowpack is rain-soaked and starting to freeze. It diminishes rapidly to dirt below 500 m.
Weather Summary
Thursday Night
Cloudy. Light rain. 5-15 cm of snow above 1000 m. Moderate south ridgetop wind. Freezing level drops from 1000 m to valley bottom.
Friday
Cloudy, possibly clearing in the afternoon. 5-10 cm of snow expected to valley bottom. Moderate to strong southwest ridgetop wind shifting to west. Freezing level at valley bottom. Treeline low around -11 °C.
Saturday
Mostly sunny. Trace of snow expected. Moderate southwest or west ridgetop wind. Treeline temperature around -11°C. Freezing level at valley bottom.
Sunday
Sunny. Trace of snow expected. Moderate southwest or west ridgetop wind. Treeline temperature around -7 °C. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Make observations and assess conditions continually as you travel.
Problems
Wind Slabs
This avalanche problem is most likely where moderate winds are moving dry snow and forming fresh slabs in leeward terrain.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Several weak layers buried between late December and mid-January are still a concern in this forecast area. Calmer, cooler weather is making them less reactive, but they might not really lock up until the weekend when it's much colder.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 2nd, 2024 4:00PM
