Avalanche Forecast

Archived

Feb 11th, 2023–Feb 12th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

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, McBride, Premier, Quesnel, Sugarbowl, Clemina, North Monashee, Renshaw, Robson.

The snow and wind keep coming, the wind slabs keep forming, so keep seeking out the sheltered zones! Don't let warm temperatures down low push you into a bad spot up high. Triggering a wind slab is probably one of the most effective ways to cause a large and destructive step-down avalanche.

Confidence

Moderate

Avalanche Summary

The AvCan field team observed fairly stubborn cracking of wind-redistributed snow at Bell Mountain on Friday, giving good confirmation of an active wind slab problem. No new avalanches were reported in the region.

Reports from Thursday included one size 1 (small) skier triggered wind slab with a 25 cm crown in the central part of the region as well as an observation one additional size 2, 50 cm-deep storm slab from the recent natural cycle. More extensive observations of this cycle were again reported farther south in the more heavily trafficked Selkirks and Monashees.

Although persistent slab activity haas been on the decline, it hasn't been totally quiet. On Wednesday, clearer weather allowed for observations of a natural avalanche cycle from the previous 24 to 48 hours. The most most notable observation here was a size 3 persistent slab avalanche that initiated on a steep north slope at 2000 m. The slab was 100-130 cm deep.

Snowpack Summary

Up to 20 cm of new snow is expected to accumulate over higher terrain in the region by end of day Saturday under the influence of strong southwest winds. This will add to 60-100 cm of storm snow from the last week with similar elevated winds.

The recent snow appears to be forming a good bond with the plethora of old snow surfaces beneath it, including previously wind-affected snow at upper elevations, a sun crust on steep solar aspects, faceted snow, and surface hoar crystals in wind-sheltered terrain.

Two layers of surface hoar crystals and/or melt-freeze crust sit in the upper meter of the snowpack. The surface hoar is most likely found around shaded treeline and lower alpine elevations. The melt-freeze crust is found up to 1800 m on all aspects and into the alpine on sun-exposed slopes. Although these layers continue to be tracked by local operators, they have not produced recent avalanches and are likely trending toward being dormant.

The most concerning weak layer in the snowpack is composed of large and weak facets from November located near the base of the snowpack. Although this layer hasn't produced avalanches recently, it continues to guide terrain selection by professionals in the region.

Weather Summary

Saturday night

Cloudy with flurries bringing about 5 cm of new snow. Light to moderate southwest winds.

Sunday

Cloudy with increasing snowfall bringing 5-10 cm of new snow, continuing overnight. Light rain below about 1400 metres. Strong southwest winds. Treeline high temperatures around -2 with freezing levels rising to 1600 meters.

Monday

Cloudy with easing flurries with about 15-25 cm of new snow, including overnight amounts. Light to moderate southwest winds, easing over the day and shifting west. Treeline high temperatures around -7.

Tuesday

A mix of sun and cloud with about 5 cm of new snow from overnight. Light northwest winds shifting southwest. Treeline high temperatures around -9.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be especially cautious as you transition into wind affected terrain.
Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.

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.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.