Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

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

Sea To Sky, Brandywine, Garibaldi, Homathko, Spearhead, Tantalus.

Wintry conditions are found in the alpine, whereas more spring-like problems are prominent at lower elevations. Travel cautiously, particularly during the heat of the day when avalanche activity is most likely.

Confidence

Moderate

Avalanche Summary

Many small to large (size 1 to 2) wet loose avalanches were observed over the weekend and on Monday, generally occurring out of steep alpine terrain between 1800 m and 2100 m. Small cornice chunks were also triggered naturally and by riders on Monday. One of the chunks triggered a a small (size 1) slab on a north aspect at 2100 m.

We expect to see similar avalanches in the coming days at all elevations during periods of sunny skies and an increasing freezing level. The likelihood of seeing very large avalanches releasing on the buried weak layer described in the Snowpack Summary will increase with each day of warming this week.

Snowpack Summary

Moist snow is found on all aspects up to 1800 m, which will freeze into a melt-freeze crust overnight. Dry snow may be found above 1800 m on northerly aspects, where wind slabs may linger in steep leeward slopes from southerly wind.

The middle of the snowpack is consolidated with various layers of moist snow, hard snow, and melt-freeze crusts.

A layer of weak faceted grains may be found near the base of the snowpack at treeline and alpine elevations. The likelihood of this layer being triggered will increase with each day of warming for the coming weeks. Humans are most likely to trigger it in steep and rocky slopes where the snowpack is relatively thin.

Cornices are large and looming at this time of year and will weaken with daytime warming.

Weather Summary

Monday Night

Mostly cloudy with no precipitation, 20 to 30 km/h southwest wind, treeline temperature -4 °C, freezing level 1300 m.

Tuesday

Mostly sunny skies with no precipitation, 10 to 30 km/h west wind, treeline temperature -1 °C, freezing level rising to 1900 m.

Wednesday

Cloudy with light snow or rain, accumulation 2 to 5 cm above 2500 m, 30 to 60 km/h southwest wind, treeline temperature 3 °C, freezing level 2500 m.

Thursday

Mostly sunny with no precipitation, 10 to 20 km/h variable wind, treeline temperature 6 °C, freezing level 3500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

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

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.

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.

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.