Avalanche Forecast

Archived

Jan 28th, 2024–Jan 29th, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural and human triggered avalanches likely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

South Rockies, Akamina, Crowsnest North, Crowsnest South, Elkford East, Elkford West.

Avoid all avalanche terrain.

Large natural and rider-triggered avalanches are expected and could run to the valley bottom.

Confidence

High

Avalanche Summary

Information is very limited but an avalanche cycle is suspected to be ongoing and to continue Monday.

Several large (size 2-3) avalanches were triggered with explosives this week. They were primarily wind slabs failing on buried facets from mid-January's cold spell about 30 to 60 cm deep.

Snowpack Summary

Up to 30 cm of soft snow is getting saturated by rain at all elevations and high temperatures. The strong southwest wind has also redistributed surface snow in the alpine and treeline. Expect the entire below treeline snowpack to be losing strength.

There is a layer of sugary facets that are buried 30-50 cm deep and in some places sits on a crust from December. This layer has been reactive in snowpack tests.

The lower snowpack contains a series of crusts and faceted snow. Expect snow depth at treeline to be 70 to 120 cm.

Weather Summary

Sunday Night

Partly cloudy with no snow, west alpine wind 25 to 35 km/h, treeline temperature 1 °C, freezing level 2250 m.

Monday

A mix of sun and cloud with no new snow, west alpine wind 40 to 50 km/h, treeline temperature 6 °C, freezing level 3500 m.

Tuesday

A mix of sun and clouds with no snow, southwest alpine wind 40 to 60 km/h, treeline temperature 5 °C, freezing level dropping to 2500 m in the afternoon.

Wednesday

Mostly clear skies with no new snow, southwest alpine wind 25 to 45 km/h, treeline temperature 6 °C, freezing level 2700 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
Cornice failure may trigger large avalanches.

Problems

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.

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.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.