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 23rd, 2022–Apr 24th, 2022

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

Regions

Northwest Inland.

Assess steep alpine features for wind slab before committing to them. Wind slabs will be most reactive where they overlie a firm crust.

Observations are limited at this time of year! Let us know what you're seeing by posting on the Mountain Information Network.

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

SATURDAY NIGHT: Cloudy with light flurries, 5 to 10 cm of new snow accumulation. Freezing level around 1400 m. Strong southerly winds.

SUNDAY: Cloudy with light flurries, up to 5 cm of new snow accumulation. Freezing level rising to 1600 m. Light to moderate southerly winds.

MONDAY: Mainly cloudy with isolated flurries. Freezing level around 1300 m. Light southerly winds.

TUESDAY: Partially cloudy. Freezing level around 1200 m. Light southerly winds.

Avalanche Summary

Several wet loose avalanches (size 1-2) were observed on steep solar aspects on Thursday afternoon as a result of strong solar radiation. 

Looking forward to Sunday, fresh wind slabs may form in lee areas in the alpine and exposed treeline. Wet loose avalanches will be possible at low elevations with rain and warm temperatures. These avalanches will likely be limited to small releases on isolated slopes in extreme terrain.

Reports are limited at this time of year. Please let us know what you're seeing by filling out a MIN report!

Snowpack Summary

New snow and southerly winds are expected to create fresh deposits of wind slab in the alpine and exposed treeline. This 5-10 cm of new snow overlies a heavily wind-affected surface in exposed terrain, the product of an intense wind event early last week. In sheltered areas, the upper snowpack is faceted from recent cold temperatures, and surface hoar may exist in isolated areas. A crust can be found on steep solar aspects and at low elevations. A more widespread melt-freeze crust can be found 20 to 50 cm deep in most areas, and up to 80 cm in the snowiest parts of the region. This crust is near the surface below 1200 m.

Terrain and Travel

  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

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.