Avalanche Forecast

Archived

Apr 24th, 2023–Apr 25th, 2023

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 possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Regions

Coquihalla, Harrison-Fraser, Manning, Skagit.

Sunny skies and a rising freezing level will increase avalanche danger during the heat of the day.

Confidence

Moderate

Avalanche Summary

The weekend saw numerous small to large (size 1 to 2) wet loose avalanches that were naturally triggered out of steep, rocky terrain features.

We expect to see similar avalanches in the coming days during periods of sunny skies and an increasing freezing level.

Use plenty of caution along alpine ridges, where cornices may be large.

Snowpack Summary

Moist snow is found on all aspects up to 2000 m, which will freeze into a melt-freeze crust overnight.

The remainder of the snowpack is strong with varying hard snow layers and bonded melt-freeze crusts.

Cornices are large along many alpine ridges.

Weather Summary

Monday Night

Cloudy with light snowfall, accumulation 1 to 3 cm, 30 km/h southwest wind, treeline temperature -4 °C, freezing level 1300 m.

Tuesday

Morning clouds and afternoon sunny skies with no precipitation, 20 km/h southwest wind, treeline temperature -3 °C, freezing level 1500 m.

Wednesday

Mix of sun and cloud with no precipitation, 40 km/h southwest wind, treeline temperature 4 °C, freezing level 2700 m.

Thursday

Mix of sun and cloud with no precipitation, 10 km/h variable wind, treeline temperature 7 °C, freezing level 3500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

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.