Avalanche Forecast

Archived

Dec 26th, 2023–Dec 27th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Sea To Sky, South Coast, Brandywine, Garibaldi, Homathko, Powell River, Spearhead, Tantalus, North Shore, Sky Pilot, Tetrahedron.

Keep terrain selection conservative

Concern is for elevations above the freezing level where sensitive wind slabs continue to build. Large human triggered avalanches were reported

Confidence

Moderate

Avalanche Summary

On Tuesday, numerous size 2-2.5 human triggered avalanches were reported (including from explosive control). A notable size 3 avalanche was reported on a west facing slope, indicating wind direction has varied throughout this region.

These avalanches all occurred at treeline and on the crust/surface hoar layer below the recent storm snow.

Please help out your backcountry community by submitting a MIN report if you head out to the backcountry.

Snowpack Summary

Continued snow and rain are expected over the day. The warm and moist snow will settle rapidly, becoming dense and presenting as a slab. Strong southerly winds have continued to transport new snow, building deeper slabs at higher elevations. This wind affected snow sits over a crust and layer of surface hoar, increasing reactivity.

Below treeline, you'll find dirt, or shallow and wet snow.

The mid and lower snowpack is made up of a series of crusts and rounded grains and is well consolidated.

Overall, the snow depth tapers rapidly with elevation and remains shallow creating challenging travel conditions and hiding early season hazards just below the snow surface.

Weather Summary

Tuesday Night

Cloudy with 5 cm of snow on the highest peaks. Freezing levels rise towards 2000 m. Southerly winds increase, 50-70 km/h.

Wednesday

Cloudy. Freezing levels begin the day at 2000 m and drop to 1600 m over the day. Up to 15 cm of snow is possible. Treeline temperature around 5 °C. Strong southerly winds continue, 70-90 km/h.

Heavy snow continues overnight.

Thursday

Cloudy. Freezing levels 1500-1800m. 5-15 cm of wet snow expected. Treeline temperature around 4 °C. Southerly winds, 60-80 km/h.

Friday

Cloudy. Freezing levels remain above 2000 m with light rain below. Treeline temperature around 5 °C. Southerly winds, 40-60 km/h.

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.
Stay off recently wind loaded slopes until they have had a chance to stabilize.
Wind slabs are most reactive during their formation.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.