Avalanche Forecast

Archived

Mar 15th, 2023–Mar 16th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Cariboos, Blue River, Clearwater, McBride, Premier, Quesnel, Sugarbowl, Clemina, North Monashee, Renshaw, Robson.

Reactive wind slabs may have formed from moderate southwest winds and recent storm snow.

Don't let good riding lure you into high-consequence terrain.

Confidence

Moderate

Avalanche Summary

A naturally triggered size 1.5 storm slab on a northeast aspect at treeline was reported near Blue River on Monday. Since then there have been no reports of avalanche activity. This is expected to change with the incoming weather.

Snowpack Summary

Moderate southerly and westerly winds have redistributed the 20 to 30 cm of recent snow and may have created wind slabs that will remain reactive to human triggers.

Below the new snow are a variety of surfaces. These include surface hoar, 3 to 10 mm, on shady slopes at all elevations, wind-affected surfaces at treeline and above, and sun crust on sunny aspects. These layers are likely to create problems in the future.

The mid-snowpack is generally strong but the lower snowpack is a different story.

The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.

Weather Summary

Wednesday Night

Clear with cloudy periods, no accumulation, winds westerly 20 to 30 km/h gusting to 40, treeline temperatures -8 °C.

Thursday

A mix of sun and cloud, no accumulation, winds southerly 10 to 20 km/h, treeline temperatures -8 °C with freezing levels rising to 1500 m.

Friday

Sunny, no accumulation, winds southeast 15 to 25 km/h, treeline temperatures -6 to -2 °C with freezing levels getting up to 1600 m.

Saturday

Mostly sunny, no accumulation, winds southeast 20 to 30 km/h, treeline temperatures -5 to 0 °C with freezing levels getting up to 1700 m.

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.
Use small low consequence slopes to test the bond of the new snow.
Avoid exposure to slopes that have cornices overhead.
Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.