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

Mar 11th, 2024–Mar 12th, 2024

Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

Sea To Sky, Brandywine, Homathko, Spearhead.

Avoid avalanche terrain on Tuesday. The snowpack is complex and under stress from new snow and wind-loading.

Confidence

Moderate

Avalanche Summary

There were numerous size 2 slab avalanches triggered by riders in the Whistler area on Sunday. They mostly occurred within recent storm snow, with crown depths of 40 to 80 cm. Explosive control also produced a few very large (size 3 to 4) avalanches that failed on the early February persistent weak layer.

Another round of storm slab avalanches is expected Monday night into Tuesday.

Snowpack Summary

Fresh storm slabs will form Monday night into Tuesday, as 20 to 30 cm of new snow with strong wind is expected. This adds to the 60 to 120 cm of storm snow from the weekend, which may not yet be settled and bonded. Alpine terrain is heavily wind-affected.

A weak layer composed of facets on a crust is buried 100 to 200 cm deep. This layer remains sensitive to both human and natural triggers and is capable of producing very large avalanches.

Weather Summary

Monday Night

Flurries with 10 to 20 cm of snow. 60 km/h south ridgetop wind. Treeline temperature -5 °C.

Tuesday

Flurries easing midday with 10 cm of snow in the morning then cloudy in the afternoon. 25 km/h southwest ridgetop wind. Treeline temperature -4 °C.

Wednesday

Mix of sun and cloud. 20 km/hr southwest wind. Treeline temperature -3 °C with freezing level rising to 1200 m.

Thursday

Mostly sunny. 15 km/hr northwest wind. Treeline temperature +5 °C with freezing level rising to 3000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy snowfall.
  • Avoid traveling in runout zones. Avalanches have the potential to run to the valley floor.
  • Remote triggering is a concern, watch out for adjacent and overhead slopes.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.

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.