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

South Coast Inland, Birkenhead, Duffey, South Chilcotin, Stein, Taseko.

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

Confidence

Moderate

Avalanche Summary

Many small to large (size 1 to 2) wet loose avalanches were observed by riders over the weekend, generally occurring out of steep alpine terrain. We expect to see similar avalanches in the coming days 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.

Use plenty of caution along alpine ridges, where cornices are likely large and weakening.

Snowpack Summary

Moist snow is found on all aspects up to 2200 m, which will freeze into a melt-freeze crust overnight. Dry snow may be found above 2200 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 is 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 km/h southwest wind, treeline temperature -4 °C, freezing level 1400 m.

Tuesday

Early morning clouds then sunny skies with no precipitation, 10 to 20 km/h southwest wind, treeline temperature -3 °C, freezing level rising to 2000 m.

Wednesday

Mostly cloudy with trace snow or rain, 20 to 40 km/h southwest wind, treeline temperature 3 °C, freezing level 2400 m.

Thursday

Mostly sunny with no precipitation, 10 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

  • The likelihood of deep persistent slab avalanches will increase with each day of warm weather.
  • 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.
  • Carefully evaluate steep lines for wind slabs.
  • Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.

Problems

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.

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.

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.