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 22nd, 2023–Mar 23rd, 2023

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

North Columbia, South Columbia, Esplanade, Jordan, North Selkirk, Shuswap, Badshot-Battle, Central Selkirk, Goat, Gold, Kokanee, North Okanagan, Retallack, Valhalla, Whatshan.

Solar-triggered loose wet avalanches and cornice releases remain a concern. Use extra caution around sun-exposed slopes during the heat of the afternoon.

Human triggering of the lingering deep persistent layer still remains possible in thin, rocky snowpack areas.

Confidence

High

Avalanche Summary

On Tuesday, numerous natural loose wet avalanches up to size 2.5 were reported between 2000 and 2700 m elevation. One of these triggered a size 3 deep persistent avalanche at 2600 m elevation which failed down 100-200 cm on the November basal layer. A couple of other natural size 2.5 slab avalanches were also reported. One natural cornice release was reported on a SE aspect at 2300 m and several other cornices were triggered with explosives. None of these cornice releases triggered slabs.

On Monday, numerous naturally triggered wet loose avalanches up to size 3 (very large) were reported on steep sunny aspects in the alpine. A helicopter landing on a ridge remotely triggered a size 2 wind slab on the steep northerly alpine slope below. A couple of human-triggered size 1 wind slab avalanches were also reported on northerly aspects in the alpine.

Snowpack Summary

Expect to find a melt-freeze crust on the surface of all aspects at treeline and below, and on sunny aspects in the alpine. Depending on the timing of the incoming cloud cover, solar radiation may break down the crust on sunny slopes throughout the day on Thursday.

30-50 cm down there is a sun crust on sunny aspects and surface hoar (3-10 mm) on isolated shady and sheltered slopes.

The mid-snowpack is generally strong but the lower snowpack is a different story.

The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern for human triggering in rocky, shallow, or thin-to-thick snowpack areas at treeline and above. Small avalanches and cornice falls also have the potential to trigger this deep layer.

Weather Summary

Wednesday Night

Clear, ridgetop winds southwest 10-20 km/h, treeline low around -10 °C.

Thursday

A mix of sun and cloud, ridgetop winds southwest 10-20 km/h, freezing level reaching around 1800 m.

Friday

Light snowfall up to 10 cm, ridgetop winds southwest 10-25 km/h, freezing level reaching around 1400 m.

Saturday

A chance of light flurries, ridgetop winds northwest 10-20 km/h, freezing level reaching around 1300 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Cornice failure may trigger large avalanches.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

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.