Avalanche Forecast

Archived

Mar 12th, 2025–Mar 13th, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Cariboos, Blue River, Clearwater, Premier, Quesnel, Clemina, North Monashee.

Conservative terrain travel is recommended, as human-triggering of large avalanches is likely.

Confidence

Moderate

Avalanche Summary

A couple large (size 2) naturally triggered persistent slab avalanches were observed in the alpine near Valemount on Tuesday. They were 100 cm deep, on east aspects, and failed on the buried weak layer described in the snowpack summary.

Otherwise, riders and explosives continued to trigger small to large (size 1 to 3) storm slab avalanches within all the recent storm snow. Most avalanches were on north to east aspects between 1900 and 2100 m and 50 to 80 cm deep.

Snowpack Summary

New snow will add to the 50 to 80 cm of storm snow since Saturday. All this snow sits on a hard melt-freeze crust found everywhere except north-facing slopes above 1600 m. There may also be isolated surface hoar crystals above the crust in wind-sheltered terrain around treeline. Southwest wind may form deeper and touchier deposits in lee terrain features at high elevations.

A weak layer of surface hoar and/or faceted grains buried mid-February is around 70 to 120 cm deep.

The lower snowpack is well-settled.

Weather Summary

Wednesday Night

Cloudy with 5 to 10 cm of snow and local amounts of up to 20 cm possible. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -7 °C.

Thursday

Cloudy with 2 to 5 cm of snow. 10 to 20 km/h northwest ridgetop wind. Treeline temperature -8 °C.

Friday

Mix of sun and cloud with 1 to 3 cm of snow. 10 km/h south ridgetop wind. Treeline temperature -8 °C.

Saturday

Mostly cloudy with 1 to 3 cm of snow. 10 to 20 km/h south ridgetop wind. Treeline temperature -5 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Be aware of the potential for large avalanches due to buried weak layers.
Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Remote triggering is a concern; avoid terrain where triggering overhead slopes is possible.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.