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 19th, 2022–Apr 20th, 2022

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

Regions

Northwest Inland.

A bit of new snow has introduced manageable wind slab and wet loose hazards in the areas it fell. Avalanche activity is unlikely where it didn't. The greatest potential is in the south and west of the region.

Confidence

Moderate -

Weather Forecast

TUESDAY NIGHT: Mainly cloudy with continuing isolated flurries and a further trace of new snow. Light east or southeast winds.

WEDNESDAY: Cloud diminishing over the day. Light east or southeast winds. Treeline high temperatures around -3.

THURSDAY: A mix of sun and cloud. Light southeast winds shifting southwest. Treeline high temperatures around -1.

FRIDAY: A mix of sun and cloud. Light southwest winds. Treeline high temperatures around -1.

Avalanche Summary

One recent cornice fall that did manage to trigger a slab was reported from a flight over the Telkwa range on Friday. On Saturday a few small loose dry avalanches were observed in steep, solar, rocky terrain. Otherwise, no new avalanches have been reported in the past few days.

On Thursday, explosives triggered wind slabs up to size 2 on south-south east aspects. On Wednesday, glacial icefall (serac) triggered a large persistent slab avalanche (size 3). This avalanche occurred on a northeast aspect in the alpine and is suspected to have failed on a crust from early April. This avalanche was only possible with an extremely large load and is not suggestive of general conditions in the region as a whole.

Looking forward, areas that received a bit of snow Monday/Tuesday will have small surface instabilities (small wind slabs, wet loose potential) to manage on Wednesday, particularly with solar warming.

Snowpack Summary

Very light new snow amounts, up to about 10 cm in the Howsons, have landed on heavily wind-affected surfaces in exposed terrain, the product of an intense wind event early last week. In sheltered areas, the flurries may have added to limited stashes of soft, potentially faceted snow. After daytime warming and a subsequent freeze on Wednesday, it will add to the growing tally of crusts on solar aspects. A 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

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

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.

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.