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

May 5th, 2021–May 7th, 2021

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

Regions

Yukon.

New snow likely formed wind slabs in steeper alpine features. Avalanche conditions could vary with elevation.

Confidence

Moderate - Uncertainty is due to difficult to forecast freezing levels.

Weather Forecast

WEDNESDAY NIGHT: alpine low -4C, wind north/northeast 10km/h, increasing cloudiness

THURSDAY: alpine low -4 high 3C, wind north/northeast 20-30km/h, mostly cloudy, 2cm new snow

FRIDAY: alpine low -2C high 3C, wind southwest 10-20km/h, mostly cloudy, trace precipitation

SATURDAY: alpine low -2C high 2, wind south 20km/h, mostly cloudy, trace precipitation

Avalanche Summary

No new avalanches have been reported since the weekend. That said, we have a similar weather pattern to last week when small wind slabs were reported in the alpine and isolated wet slab avalanches were reported at lower elevations. 

Snowpack Summary

Between last week and this week we have accumulated up to 30cm of dry snow in the alpine above 1600m. Some of this snow has likely been blown into wind slabs in specific terrain features. Below 1600m the upper snowpack is isothermal, moist, and mushy. 

The lower snowpack in White Pass is deep for this time of year with no layers of concern. Areas further inland, such as the Wheaton Valley, may have a shallower and weaker snowpack.

Cornices are still very large. Recent cold temperatures have kept cornice failures to a minimum but they should always be treated with respect in the spring, especially when the air temperature rises.

Terrain and Travel

  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Be carefull around freshly wind loaded features.
  • Avoid exposure to slopes that have cornices overhead.
  • Firm cornices can pull back into flat terrain at ridgetop if they fail.
  • Keep in mind that wet avalanches can be destructive due to their high density.

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.

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.