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 8th, 2022–Apr 9th, 2022

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

Northwest Coastal.

Fresh storm slabs are expected to remain sensitive to human triggering this weekend, especially in wind loaded terrain. Start on smaller terrain features and gather information before committing to bigger terrain.

Confidence

Moderate - Uncertainty is due to field data and reports showing a wide variation in conditions throughout the region.

Weather Forecast

FRIDAY NIGHT: 2 to 6 cm of snow, moderate west wind, freezing level near valley bottom.

SATURDAY: Broken cloud cover, no significant precipitation expected, moderate north/northwest wind, freezing level beginning near valley bottom, rising to around 800 m.  

SUNDAY: Broken cloud cover in the morning giving way to scattered cloud cover in the afternoon, no significant precipitation expected, light northeast wind, freezing level beginning near valley bottom, rising to around 1200 m in the afternoon. 

MONDAY: Clear skies at dawn with cloud cover increasing to broken after lunch, potential for some light flurries/rain in the afternoon, moderate south wind, freezing level beginning near valley bottom, rising to around 1000 m in the afternoon. 

Avalanche Summary

Observations were a bit thin on Thursday, but this MIN sums it up very well. Up to 50 cm of new snow producing audible avalanches in big terrain, and smaller storm slabs in more moderate terrain.

On Wednesday, a few large wind slabs up to size 3 as well as several storm slabs to size 2 were triggered with explosives. Several small natural dry loose avalanches were reported, as well as a large (size 2.5) cornice failure. Skiers triggered several small wind slab avalanches in the alpine. 

Snowpack Summary

20-50 cm of new snow adds to the 30-60 cm of recent snow, which overlies a hard melt-freeze crust. The previous snow surface was wind affected and in some wind-exposed areas the wind had scoured the snow down to the crust. 

Around 100 cm down, a layer of weak snow (facets or surface hoar) has been occasionally reported in sheltered areas. The distribution of this layer has been reported as isolated and is likely not a problem in many areas.

Cornices are very large and exposure to them should be minimized, especially during warm or windy weather.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Keep in mind the crust offers an excellent bed surface for avalanches.
  • Even brief periods of direct sun could produce natural avalanches.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

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.

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.