Avalanche Forecast

Archived

Mar 29th, 2025–Mar 30th, 2025

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 unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Brandywine, Garibaldi, Spearhead, Tantalus.

Sunshine can have a powerful effect on stability - and your desire to push into aggressive terrain. Deep instabilities are still present and have produced recent large avalanches.

Confidence

Moderate

Avalanche Summary

A widespread, very large avalanche cycle (up to size 4) occurred throughout the region on Tuesday and Wednesday. Many slabs failed on or stepped down to persistent weak layers.

On Thursday, a few natural and human-triggered size 1-2 storm slabs were observed. By Friday, storm slab activity was limited to explosive control work. Small natural and skier-triggered loose wet were also reported.

Snowpack Summary

10 to 20 cm of snow from Saturday sits over a crust capping a wet upper snowpack. At wind-exposed elevations, southerly wind has likely redistributed the recent snow into deeper deposits on northerly aspects.

Several persistent weak layers from January, February and March can be found between 1 and 3 m deep. These layers were very reactive during the warm spell last week. Below this, the snowpack is well-settled and strong.

Weather Summary

Saturday night

Clearing. 10 to 20 km/h southeast ridgetop winds. Treeline temperature -3 °C. Freezing level around 1200 m.

Sunday

Mostly sunny. 30 to 40 km/h southeast ridgetop winds. Treeline temperature +2 °C. Freezing level rising to 1900 m.

Monday

Cloudy, with 2 to 6 cm of snow above 1200 m, light rain below. 10 to 25 km/h variable ridgetop winds. Treeline temperature -2 °C. Freezing level 1400 m.

Tuesday

Mostly sunny. 30 to 40 km/h northwest ridgetop winds. Treeline temperature -2 °C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be aware of the potential for large avalanches due to buried weak layers.
Cornice failures could trigger large and destructive avalanches.
A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.

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.

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.