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 19th, 2022–Mar 20th, 2022

Alpine
Natural avalanches possible, human triggered probable.
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.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

Sea To Sky.

Carefully assess the wind slab hazard as you gain elevation. Rider triggerable wind slab will likely be found in exposed terrain.

Confidence

Moderate -

Weather Forecast

Saturday night: flurries bringing up to 5 cm of new snow with moderate southwest ridgetop winds. Low of -8 at 1500 m.

Sunday: cloudy with light flurries bringing up to 5 cm of new snow. High of -2 at 1500 m. Moderate to strong southwest winds.

Monday: cloudy with around 5cm of new snow expected. Moderate to strong southwest winds and freezing levels rising to 1600 m. 

Tuesday: cloudy with 5 cm of new snow expected with strong southwest winds. Freezing levels rising to 2100 m.

Avalanche Summary

Over the past few days skiers have triggered wind and storm slab avalanches up to size 1.5. Most of this avalanche activity has been on north aspects and at or above treeline. We suspect more of this type of avalanche activity will be reported on Saturday.

Snowpack Summary

Wind slabs can be found on north and east aspects at treeline and above. 20 to 40 cm overlies surface hoar in shady, wind-sheltered areas and a hard melt-freeze crust on all aspects below 1500 m and on sun-exposed slopes into the alpine.  

Around 50-80 cm deep, a weak layer of facets may be found above a melt-freeze crust that formed in February. This layer had been most reactive on north and northeast aspects between 1600 and 2100 m. While this layer is now likely dormant in most areas, it still remains a concern for professionals in the region and could still be capable of producing isolated large avalanches if triggered. Check out this forecaster blog for more info.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.

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.

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.